Must Catholics believe in Christ's historicity? Is there some philosophical doctrine in Catholicism which does not require to believe in the historicity of Christ, like in Buddhism (you can "believe"/practice Buddhism, but don't believe in Buddha and his historicity)? I ask it because I can believe in symbol or philosophical concepts but not in those Bible stories, they sound absolutely immodern, naive and untrue. I know about Pierre Teilhard de Chardin, but I don't know what is the current status of his doctrine in Holy See.

Also, it's super difficult to me to believe in a soul and anthropomorphic God... And believe in soul makes close death very difficult, you know, hope is a pain, sleep is a rest. Maybe there are some more symbolic or philosophical or mystic concepts in Catholicism for peoples like me? Like there are such ones in Islam and Buddhism?
Yes, Catholics must believe in the historicity of Christ.


  Is there some philosophical doctrine in Catholicism which does not require to believe in the historicity of Christ


No. This is the heresy of Modernism, whose philosophical foundation is agnosticism.

Pope St. Pius X condemned the following proposition as heretical in Lamentabili Sane (1907):


  
  It is permissible to grant that the Christ of history is far inferior to the Christ Who is the object of faith.
  


In Pope St. Pius X's encyclical Pascendi Dominici gregis (1907), he writes (§6):


  …it is inferred [by the Modernists] that God can never be the direct object of science, and that, as regards history, He must not be considered as an historical subject.


See also Pascendi §§ 9-10, 16-17, and esp. 29-33, and passim.

De Chardin was a heretic censored by the Holy See. cf.:


Teilhardism and the New Religion: A Thorough Analysis of the Teachings of Pierre Teilhard de Chardin (1988) by Wolfgang Smith