I like to do the once weekly 50% water changes. A full 50% might not be needed since you have one baby, but I'd wait and make that final call when the cycle gets into full swing. Don't want to upset the cycle too much.
I feed my youngest one 3-4 times a day. I give him 2-4 bite-sized pieces (well depending on how good my cutting skills are that day, they sometimes end up a little smaller). But this is with a water temp of 78F. At your water temp between 2 and 3 times a day would be good. Some days my schedule doesn't allow for that many feedings, but I make sure to get in at least one a day.
Koko's is probably recommending reduced feeding to help keep water quality from degrading when you're treating for a disease. Poor water quality is the number one cause of disease, so any way we can improve it helps your goldy's chance of recovery. But Prazi is a pretty standard treatment. I'd keep feeding him at least once a day. Good nutrition is also important on the road to recovery.