Polychrome, I always try to have at least 300 in the food bin. The villagers seem to improve healthwise after that point, anything less, and they seem to either remain stable, or get worse

Can't help you in deciding if force feeding them does improve their strength, but I like the sound of that at least. Also, I saw at some stage someone else saying that letting the villagers go off and do their little explorations (and other seemingly useless tasks) seems to give them a new lease of life....dunno, but again, sounds good

I have had a few villages where my male/female ration was a bit wonky. I think I even got down to 2 males and 2 females, and still managed to get the village back. It just takes a little planning, a lot of watching, and a huge amount of patience. I basically just kept one woman on permanent breeding duty, and let the other villagers take care of everything else. gradually, the numbers did start evening out again. The big tip here, while I was not watching the game I ran it either on slow mode, or actually paused it if I was to be away a long time. This way, I was more in control of what happened