Hi Ben

Make sure you check your villager's preferred skill in the detail screen -- they will usually perform that skill on their own as long as it's the skill they have the most experience in, and they have at least a trainee level.
no lab coats, sorry -- not all scientists wear them

400 food in the bin is a good milestone for starting to raise your population...but don't let it get out of hand (stay below 15 people) until you get fishing.
Once you have 400 food, you can probably stop pausing the game when you quit. But keep checking frequently until you've finished the game -- especially if you don't have fishing yet

.
Any villager can heal, just like any villager can build, fish, breed, or research.
Good luck!
-- jen