Do any Protestant Sects object to the existence of angels? I'm kind of more-or-less asking this because CHRISTIANITY.SE IS GOING TO GET A REAL HAIRCUT soon, but I was thinking about Christian symbols and Jewish symbols and symbols that everyone agrees one and furthermore everyone feels comfortable engraving. 

Everyone's Bible's got this in it


  Exodus 25:17-22 (NIV)   
  
  17 “Make an atonement cover of pure gold—two and a half cubits long and a cubit and a half wide. 18 And make two cherubim out of hammered gold at the ends of the cover. 19 Make one cherub on one end and the second cherub on the other; make the cherubim of one piece with the cover, at the two ends. 20 The cherubim are to have their wings spread upward, overshadowing the cover with them. The cherubim are to face each other, looking toward the cover. 21 Place the cover on top of the ark and put in the ark the tablets of the covenant law that I will give you. 22 There, above the cover between the two cherubim that are over the ark of the covenant law, I will meet with you and give you all my commands for the Israelites.


And even the Jews who 5 seconds ago were prohibited from making graven images of God are commanded to make some sort of "cherubs".  So, what would be the reason, if any, for a Christian group today to avoid angels?  What's the most nuanced possible understanding of Exodus 25 that could justify an iconoclast who would even iconosmash the Ark of the Covenant
They are not making an idol or a graven image (an idol) of God by putting a cherubim (These are not the heart arrow cherubs) on the Ark of the Covenant. They are not worshiping the cherubims, they are worshiping God.
I have not found a denomination that doesn't believe in angels (see this comparison of denominations), so for what I know of there isn't (This is not including a few people that don't, this is groups).
And to answer your question, there is no reason a Christan group shouldn't believe in angels. Angels are mentioned 273 times in the Bible!