What are the main differences between Jehovah's Witnesses and Biblical Unitarians? What are the main differences between the two? I know that both reject the trinity and the divinity of Jesus, but that's about it. I'm particularly interested in knowing their doctrinal differences (if any) with regards to the following points:

Christology,
Pneumatology,
The nature of God,
Soteriology,
The nature of humans (what happens to us when we die),

and any other important doctrinal aspects in which they part ways.
Introductory Notes:
CSE = Christianity Stack Exchange   BU = Biblical Unitarianism  JW = Jehovah’s Witnesses
CSE Tag Unitarianism = a liberal Christian theological movement (from 1565) known for its rejection of the doctrines of the TRINITY, Original Sin, Predestination and Biblical Inerrancy.
CSE Tag Universalism = In Christianity, Universal Salvation is the belief that all humans will be reconciled to God.
CSE Tag Canon = books considered to be authoritative as scripture.
Main link for all articles on Biblical Unitarianism:  https://www.biblicalunitarian.com/articles
Please note: Biblical Unitarianism is not to be confused with Unitarian Universalism.
Both groups consider the Bible to be authoritative scripture. Any biblical references are to be found in the links provided.
I neither support nor endorse the beliefs of either Biblical Unitarians or Jehovah’s Witnesses.
Christology – Study of the person of Christ, his humanity and divinity, his nature and work:  https://en.wikipedia.org/wiki/Christology
BU – Jesus is NOT God.  They reject the Trinity. There is only one True God, the Father, and Jesus Christ is the “man accredited by God” who has now been made “both Lord and Christ” (Acts 2:22 and 36). Christ is fully man and is “one of us,” and God is God and has never changed or been a man.  https://www.biblicalunitarian.com/verses/philippians-2-6-8   Jesus is the Son of God.  He did not have a pre-human existence.  He came into existence when God created Jesus’ life in Mary.  He was born without sin.  He was resurrected with an incorruptible body and exalted in heaven to God’s right hand and given all authority under the Father.  Jesus was the perfect and ultimate sacrifice for all men’s sin and is the mediator between God and men.  Jesus remains a finite, separate being with a beginning.  https://www.biblicalunitarian.com/articles/who-is-jesus-christ  See also: https://www.biblicalunitarian.com/articles/jesus-is-the-son-of-god-not-god-the-son
JW – Jesus is NOT God.  They reject the Trinity.  Before he became human, Jesus was created by Jehovah as the mighty spirit creature known in heaven as Michael the Archangel.  https://www.jw.org/en/bible-teachings/questions/archangel-michael/   Jehovah created everything else through Jesus.  God’s “only-begotten son,” the Word, was a spirit person like his Father but later “became flesh,” residing among mankind as the man Jesus.  Completing his earthly course, he was “put to death in the flesh, but [was] made alive in the spirit.” His Father resurrected him, granted his Son’s request to be glorified alongside the Father with the glory he had had in his pre-human state and God made him “a life-giving spirit.” https://wol.jw.org/en/wol/d/r1/lp-e/1200004211  See also: https://wol.jw.org/en/wol/d/r1/lp-e/101998883#h=8  and ‘His Origin was from Early Times’ here: https://wol.jw.org/en/wol/d/r1/lp-e/2005681
Pneumatology – Study of the Holy Spirit, the person and works of the Holy Spirit:  https://en.wikipedia.org/wiki/Pneumatology
BU – God is Spirit and is referred to in Scripture as the Holy Spirit.  Since God is “holy” and also a “spirit,” “Holy Spirit” is simply another name for God the Father.  God gives the gift of the new birth – his holy spirit – his divine nature.  https://www.biblicalunitarian.com/articles/what-is-the-holy-spirit  https://www.biblicalunitarian.com/articles/gods-gift-of-holy-spirit-a-he-or-an-it
JW – God is Spirit and the holy spirit is his active life force/power/energy.  The invisible energizing force that God puts into action to accomplish his will. It is holy because it comes from Jehovah, who is clean and righteous to the highest degree, and because it is God’s means to accomplish what is holy.  It is not a person and does not have personality.  https://wol.jw.org/en/wol/tl/r1/lp-e?q=holy%20spirit
Nature of God – Study of God’s attributes and being, Omnipotence, Omniscience, Omnipresence: https://en.wikipedia.org/wiki/Attributes_of_God_in_Christianity
BU – God alone is the creator.  Jesus does not have the divine attributes of omnipotence or omniscience (John5:30; Matthew 24:36; Mark 13:32) which suggests that God the Father does.  https://www.biblicalunitarian.com/search/%22Nature%20of%20God%22    https://www.biblicalunitarian.com/100-scriptural-arguments-for-the-unitarian-faith
JW – Jehovah created the spirit who came to earth to be born as Jesus.  Everything else was created through the pre-mortal Jesus.  Jehovah is omnipotent and omniscient (all-knowing), and has the divine ability to see and to know everything, but chooses to be selective with foreknowledge.  However, omnipresence is not applicable to Jehovah God: “God being an individual, a Person with a spirit body, has a place where he resides, and so he could not be at any other place at the same time.”   https://wol.jw.org/en/wol/d/r1/lp-e/1981122#h=7:0-9:545  See this article for Jehovah’s exercise of selective foreknowledge: https://wol.jw.org/en/wol/d/r1/lp-e/1970567 and this article on omnipotence: https://wol.jw.org/en/wol/d/r1/lp-e/1200001549?q=omnipotence&amp;p=par
Soteriology – Study of Jesus’ role in Salvation, Sin, Redemption, Atonement, Justification, Universal Reconciliation:  https://en.wikipedia.org/wiki/Soteriology#Christianity
BU – Jesus, born without sin, is the perfect and ultimate sacrifice for all men’s sin.  He has been made heir, exalted to God’s right hand and given all authority under the Father.  To the faithful he offers the like distinction and honor that he has with the Father, to sit with him in his throne (Revelation 3:21).  Christ is the first begotten of the dead (Revelation 1) and is ordained of God to be the judge of the quick and the dead (Acts 10:42).  https://www.biblicalunitarian.com/articles  https://www.biblicalunitarian.com/articles/if-jesus-isnt-god-how-did-he-forgive-sins  https://www.biblicalunitarian.com/articles/how-can-a-man-atone-for-the-sins-of-mankind  https://www.biblicalunitarian.com/articles/why-did-jesus-have-to-suffer-and-die
JW – Although perfect, Jesus could have sinned, but did not.  Jesus is the mediator of the new covenant which applies specifically to the 144,000 who have a heavenly hope. See ‘Those for Whom Christ is Mediator’:  https://wol.jw.org/en/wol/d/r1/lp-e/1200002957?q=Jesus+mediator&amp;p=doc    He sits in heaven, at the right hand side of Jehovah.  Since 1914 he has been ruling, from heaven, as King.  At Armageddon he will return to judge wicked humanity, accompanied by all the heavenly hosts, and then will reign over the earth for 1,000 years.  After all things have been subjected to him, he will hand the kingdom over to Jehovah. See the last section ‘Where is Jesus Today’: https://wol.jw.org/en/wol/d/r1/lp-e/2005681  https://www.jw.org/en/library/books/gods-kingdom/promises/kingdom-enemies-removed/
Life after Death – Includes Christian eschatology, Heaven in Christianity, Christian views on hell, and Intermediate state.   https://en.wikipedia.org/wiki/Afterlife#Christianity
BU – I could not find anything on life after death, heaven, hell, the intermediate state or the human soul continuing to exist after the death of the body.  Only this: “To the faithful he [Jesus] offers the like distinction and honor that he has with the Father, to sit with him in his throne” (Revelation 3:21).  Regarding eschatology, this quote from 1 Timothy 6:14-16: “To keep this command without spot or blame until the appearing of our Lord Jesus Christ, which God will bring about in his own time—God, the blessed and only Ruler, the King of kings and Lord of lords, who alone is immortal and who lives in unapproachable light.” https://www.biblicalunitarian.com/100-scriptural-arguments-for-the-unitarian-faith
JW – There is no such thing as an immortal soul. The immortal soul doctrine is pagan.  All who die await the resurrection when they will be brought back to life in physical bodies and have 1,000 years in which to earn the right to live forever on a paradise earth.  Any who fail the final test will be annihilated.  There is no such thing as eternal punishment in a literal hell.  Only 144,000 persons since the time of Jesus can go to heaven, there to rule with Christ Jesus over the inhabitants of a paradise earth.  https://wol.jw.org/en/wol/d/r1/lp-e/1200004192?q=immortal+soul&amp;p=par  https://wol.jw.org/en/wol/d/r1/lp-e/2003841?q=paradise+earth&amp;p=par
You ask if there are any other important doctrinal aspects in which Biblical Unitarians and Jehovah’s Witnesses part ways.  Theologically, the most important issue is the person of Jesus Christ, and who he REALLY is.  Both Biblical Unitarians and Jehovah’s Witnesses have a different take on Jesus, the former claiming he did not exist till God created his life in Mary, and the latter claiming he was created as a mighty spirit creature, known in heaven as Michael the Archangel, through whom everything else came into existence.  It is easy to find out what Jehovah’s Witnesses believe about life after death, the resurrection and where they expect to spend eternity.  Not so with Biblical Unitarians. I was unable to find information from the official BU web site on human nature, life after death, heaven, hell, or a resurrection. https://www.biblicalunitarian.com/category/articles
Perhaps the biggest difference is that Biblical Unitarians are liberal and they are not dogmatic. Neither do they insist on people adhering to any view they support.  They are not a religious denomination and do not appear to have a hierarchical structure.
Jehovah’s Witnesses, on the other hand, claim to be Jehovah’s earthly organisation and their Governing Body is part of “the faithful and discreet slave” who dispenses spiritual food.  The rest of religion is part of ‘Babylon the Great’.   https://en.wikipedia.org/wiki/Governing_Body_of_Jehovah%27s_Witnesses#:~:text=The%20Governing%20Body%20of%20Jehovah's,administers%20the%20group's%20worldwide%20operations  Also, a baptised Witness can either be disfellowshipped (for unrepentant rule-breaking) or be deemed as disassociated.  https://www.jw.org/en/search/?q=disfellowship
Further Reading:
Background information on Biblical Unitarianism: https://en.wikipedia.org/wiki/Biblical_unitarianism#:~:text=Biblical%20Unitarianism%20encompasses%20the%20key,but%20may%20not%20be%20divine
This JW link answers questions on their beliefs: https://www.jw.org/en/search/?q=our+beliefs
The Unitarian Universalist Church: https://www.biblicalunitarian.com/articles/does-the-unitarian-universalist-church-hold-to-the-bible-as-the-word-of-god