[Edi]

A unit decreases 5 fatigue every turn it does not attack (so when past 100, every turn). If it has reinvig 5 on top of that, it decreases that by 10. Hence, the fatigue is capped at 190 because every time it hits 200 and goes over, that's damage and the actual fatigue drops by 10.

This is not goddamn rocket science. Reading the manual and then observing the bloody mechanics in action would answer most of these questions right out and applying the knowledge gleaned from there would allow you to figure out the rest without trouble.