An unmedicated chick starter is fine. I used that or you can use gamebird and turkey starter. You want to keep the protein level in the crumbles around 19% for the first 8 weeks. for the first week, it helps to slightly moisten the crumbles in a small dish (easier for them to eat, i had a baby duck nearly choke to death once). You can add scratch to their food in small quantities every week until you get to the ratio 1:2 or 1:1 (scratch:feed). After 8 weeks, you can switch them to layer pellets or crumbles (Pellets seem better for older ducks, less choking hazzard and less messing). It works better if you slowly introduce the new layer feed by mixing it in with the starter crumbles and a higher ratio each week.
Shaving are fine, but for the first couple days you can put paper towels over the shavings until they are settled... they will try to eat shaving and investigate them but that is normal. I usually wait a week before giving them fresh greens, just because you don't want to over stimulate or freak them out. After a week of settling in, you can give them cut up green beans, or lettuce. they will be happy.
If you want to let your babies swim, wait until they are at least a week old. You can fill a pan or bath tub with an inch of warm water (They should be able to stand in it easily.) Do not use cold water, or they will get chilled. Let them play for a little while, supervising them the WHOLE time. Afterwards, dry them off using a towel or a hair dryer on low heat. Make sure you leave their lamp on even when they are not in the brooder so it stays warm...
Hopefully this helps a bit!