I'm about to start playing this game, but right now the image doesn't look very smooth (As if the screen refresh rate doesn't match the FPS a little).

Can you answer some questions:

a) Is it possible to enable FPS display in the game itself?
b) Is it possible to add a resolution higher than 640x480 to the game?
c) What measures can be taken to make the image smoother in this game?
d) Is there a FPS limit in this game (if yes\no, how to remove it\add it)?
e) Is it possible to enable\disable frame synchronization (VSYNC) in this game?
f) What is the best screen refresh rate to set in this game for VGA resolution 320x200, as well as for VESA resolution 640x480?

I use both DOSBOX and real hardware. In the second case, the game now works noticeably better (and this option would be more preferable for me), but still not as good as many other games (Quake, Duke3D, etc.). I would like to optimally adjust the image in this game before starting the walkthrough. But I didn't find any ready-made guides and recommendations for this game. Maybe there are some unofficial fixes/improvements for this engine (True 3D)? Thank you for any tips.