It would be nice if repair happened automatically for any unit that doesn't move.  It would spead up gameplay.

There are a few (albeit rare) instances where you'd rather a unit didn't repair.

 

I second this. If i did not move/ attack with the unit, it would be great for the system to auto repair any units that did not take an action when I click "done with my turn".

 

I can't think of a situation where I'd want a unit to have less health than it could do... unless for some reason it was strategically important that they die.. in which case I would move said unit to a less inconvenient location.

+1 to automating the process

I like it to be optional through a checkbox.

Checkbox, yes.  This has been discussed.

Best is probably a new unit order "Repair, Don't Repair This Turn, Deselect Unit"

Super-King, the situation would be something like you have only one spot to attack something that you know is coming next turn, but two units, and you want to guarantee the first dies so the second can also attack.

 

I have a proof of concept for this done in Greasemonkey... stay tuned!

Actually now you mention it.. I have had at least one situation where a unit stubbornly refusing to die disadvantaged me - one time there was an infantry fight going on in a little chain of mountains. I attacked with a weak unit, expecting it to die so I could replace it with a healthy unit from behind. Instead it was left with 1 health, and so my opponent killed it and advanced their infantry column one place along the mountains because of it.

Maybe a one-button approach - Just click the "Repair all units" button and every unit that can repair, does.

I say no.  Repair your own units.

 

FYI: this feature is available in the script that pluto and I are working on:
http://www.weewarscripts.info