I set the beacon at the movie theater as required by the quest, and it has been growing slow but steady. It really doesnt have the resources to grow too fast, though, so that is probably why it hasnt blown up. I would assume the robot farm would blow up, with all the free food there.
Yeah, you need one food, water, and bed for every settler. I put in a few pumps, a bunch of whatever food I have handy, and as many sleeping bags (lowest requirements) as I can cram in, and go off and run a few missions, viola, 10 or more settlers.