Hello, is it possible to play this game on 144 FPS? Perhaps there is a file that you can edit to change the 60 FPS cap or a fan-made fix.

Another question I have is are there any in-game or file settings for the mouse sensitivity? It's too sensitive for me, and I was curious if I can change the game to fix it or if I need to change my mouse settings of the computer. Thanks.

Unfortunately I can't help you, I don't know how to change fps cap or mouse sensitivity in-game. Perhaps there really is a way, but I don't know of any, sorry.