About infirmary time, in some future I will add option for calculating it based on other factors than health.
This will allow some break time because of stress or reduce recovery time for unit with lot of health.
Another benefice of this would be that in even longer run it will be able support surgery rooms that reduce time to recover.
This is a cool idea. Anything that increases the RPG element enhances the game in my opinion.
If you do this you should make it so you can't just sack a soldier that is on leave or injured. I already think that should be an optional enforcement in the game limiting the number of soldier sacking you can do. (Maybe you can sack 1 out of every 10 you hire?) Don't these soldiers have contracts? Workers comp? Severance pay? No, you can just fire them when they take a bullet to the chest for your cause!
Same for firing soldiers with low stats. This is the alien apocalypse, not the NFL draft.
Realistically you wouldn't have an endless supply of expert soldiers you could cycle through hiring/firing on a whim.