select the joints on your rig and edit>keys>bakesimulation that will transfer all the animation from your rig to the fk skeleton you can also set a checkmark in your fbx exporter. Also, check in unity under animation compression. That can cause some jitteryness as well.
I'm loving this project - it'll be great to see where you take it! With regards to UV Unwrapping, what modelling package are you using? In Maya, I have set a hotkey for 'AutomaticUnwrap' with these settings: This splits up the UVs into uniformly-sized UV islands based on a cube projection. Then I have a hotkey for…