LBD, you don’t say how old your kitten is, but they can have KMR or goat’s milk which IMO is better, until they are weaned or even long after they are eating solid food. A little change in the stool is normal whenever you change food, but diarrhea that is very frequent, and that has gone on longer than a few days is not normal and the kitten should be seen by a vet. Most all kittens have worms and the vet can prescribe meds for that and sometimes other internal parasites that will take a different med after a stool sample.
I don’t see a problem with the kitten not drinking water from a dish as most cats have to learn how to do that and the wet food they eat will contain most of the moisture they need. Kittens usually stick their heads into the water (since it’s clear) and they sneeze, spit and sputter until they figure it out. It aggravates me that a Pet Smart employee would push weaning food as little kittens don’t need a ‘weaning food’. Just milk, then wet food as they get their teeth. These links should help, please take a look at them as they will answer a lot of your questions.
http://www.safehavenforcats.com/newborn.htm
http://messybeast.com/handrear.htm