As far as the mouse goes, the game has negative mouse acceleration forced on with no option to turn it off. How a game company can make a pc shooter and leave negative mouse accel on is beyond me. But there is a mod you can download somewhere on nexus that fixes this issue. There is a separate issue that causes your frames per sec to affect your mouse aim and changing graphics settings can wildly affect your sensitivity. Idk if mods can fix that part. I ended up refunding the game after about 2 hours of play because of all that plus getting soft locked and having to restart in the first 10 min

However if youre interested in playing on controller i have heard it works very good. I just can stand playing shooters on controller