I've raised ducks and other water fowl for years. We too, also got some ducks from TSC. Within 2 days of having them, we introduced them to water. They love it! You can fill up a large bowl or bucket and let them swim around.
Well I would at least wait until they are old enough to lay eggs (which is around 4 1/2 to 5 months old.) The reason I wait for them to able to lay eggs, is so that when you do let them out, they know to go into the coop to lay the eggs. Otherwise, they will go lay the eggs in a "secret nest."
I usually just use a feeder. I will fill it up and let the chick's just eat out of it until they're full. Once the feeder is empty, I'll fill it back up. There should always be food available for growing chick's. :)
That's interesting. Chicken's know when others are sick or dying (I'm not saying yours is dying.) That might be why they are pecking on her. I've had chickens do the same thing. If she is blind, then she's most likely going to die because there is no way of keeping her alive. I don't know what...
I raised my bantams with the large breed chick's so that they would be used to each other! I think that it's important that you do, because when they get older, they might pick on each other if you put them together. It shouldn't hurt. Just watch them carefully! :)
Are they drinking water? That's very important. When you get chick's from a place like TSC, they could be going under a lot of stress. Make sure they are at least drinking some water! Or they could also just be really mellow and tired. Hope they get better!
He could possibly have mites. I would buy some Sevin's Powder and sprinkle it on all the chickens. You can buy the powder at usually any hardware store or somewhere that sells insecticides. This will kill the mites. Chickens can also get a bad habit of pulling out their feathers. I'm not sure why.