Thanks for the detailed review!
I agree selecting heroes is a bit awkward. I didn't have time to fix it up unfortunately.
With "hero style", in hindsight I think it would have been better to be able to select soldiers (and heroes) directly using a drag selection. I will probably change this after the jam voting ends.
Tooltips! I absolutely realise that it is something players need. It was bugging me during the whole jam. It was the next thing to do before the final submission, but my brain at the time just wasn't ok with doing more UI code. :)
More than one stockpile is very useful to reduce the travel time between picking up resources and dropping them off. It increases your income much faster with less people.
More hospitals isn't that useful as there's usually a clear path between someone downed and the center of the map.
Laboratories can fit an infinite amount of scientists, so not useful in this jam release, but I did have a task to set a limit to the number of scientists per building, but ran out of time.