We'll likely have to wait until TaleWorlds Entertainment issue a patch before Mount and Blade 2: Bannerlord's loading and crashing issues get fixed, but in the mean time, here's how to get the game as smoothly as possible using its Performance menu. I've yet to become mired in the same loading time issues and mission crashes as she has, so I'm afraid I can't offer any quick fixes for those unfortunately, but what I can talk about is how the game runs more generally, and how to make sense of its various graphics settings to help you get the best experience from Mount and Blade 2: Bannerlord, as well as the best performance.
Mount and Blade 2: Bannerlord has finally charged into early access, albeit with quite a number of technical issues in tow if Sin's early experience is anything to go by.