Hi Ben, the villagers are quite annoying and you have to keep putting them back to do what you want sometimes, until they learn how to do it for themselves. On the details screen, the boxes on the right can be ticked and then your villager will prefer this job: so if you ticked farming they should continue to forage, if you tick builder they will work on building projects ect.
I love the idea of lab coats but I've been playing for a while and none have shown up. You can change their outfits though by pressing F6 but be careful cos once you get to the last outfit you can't go back. There is a very detailed post with pics of the outfits in order on this forum, it's probably worth looking at that first.
As for how much food, mine seem to be happy as long as the food is over about 500. I can't remember exactly how much you need before they'll disappear into the shed but it does say they are to worried about food, as soon as they stop running away keep it above that level.
The first night I left my game running on half speed and about 5 people died, so for the first few nights I paused it. Now I've got a thriving village, loads of food and need a gazilion tech point I leave it on.
And yes any body can heal. I was thrown into a panic when my Doc got ill but thankfully the ever reliable 'Village Idiot' set me right on that.
Hope all that helps. As for being impatient, it's defiantly a game to have going on while doing other things.