Hello, person who decided to come and see what this is about.
I'll keep it as simple as I can, Playing Dragonborn and heading into the black books. 1) Is it normal you're forced into 1st person view? 2) Is it also normal I can't look up and down, nor get out of the 1st person view? 3) At the Black Book hidden in the mine, when I go out of it, i'm still stuck and I can't save the game anymore.

I'd really love if anyone could help me with this, it's been really bugging me!

- Kurai

When you enter apochrypha through a Black Book your game will create an autosave.
This is what causes your character to momentarily freeze. I have read about glitches that may occur if you have any autosaves enabled.
For game performance and to reduce savegame bloat its best to turn off all autosaves anyway, so Id start with that and see if it helps.

Good luck.