Sounds to me like you might as well wait. It's not going to get any more expensive and it's only going to get better in the future.
Sound Channels, Number of Ragdolls, Number of Corpses, Battle Size, etc. Try setting Overall to Low and then bump settings up one at a time, when your FPS drops you'll know what settings are affecting it.
Bannerlord is pretty CPU intensive, just by googling it seems that Shadow of the Tomb Raider is a lot more GPU dependant. Try to lower settings that have an impact on the CPU usage, raise the process priority and close background applications. I max out my i5-9400 in sieges with ~500 troops.
Just press yes and it should load just fine. Once you save the next time it will be updated to 1.0.1.
yep, that indicates the version of the native module.
C:\Users\<username>\Documents\Mount and Blade II Bannerlord\Game Saves\Native
+1, indeed it seems they are somewhat proceduraly generated. All companions seems to have the same starting stats as well, at least based on the ones I looked at.