Hi. Just wondering if it's possible to toggle mouselook on, without having to hold U, as in being able to move while looking with the mouse?
I realize the enemies are probably all on the same "plane" like Doom but I still like to be able to mouselook around.
I'd prefer that to the mouse moving me anyway.

Yes, just go into the Setup program. Then go to:
Controller setup ==> Setup Mouse ==> and hit the spacebar where it says 'Mouse Aiming is a toggle button'.

Check out this thread. That'll get you full, proper mouse look.

This is now the link:

https://www.gog.com/forum/blood_series/bmouse_0_5_mouse_driver_that_fixes_the_terrible_mouselook_on_dos_build_games