I seem to be one of the lone few here that feed every day. (Just once a day though.) BUT, I only have one clown in my tank at this point and it's pretty easy to just drop food in bit by bit until he's done eating. As long as my water parameters stay perfect, I probably won't change. At least until I get another fish in the tank!
Regarding what to feed the clown, my rotation of food is...
frozen mysis/small Formula 1 (omnivore) pellets/frozen mysis/Prime Reef flakes
... and then I repeat the cycle. Occassionaly, I throw in some frozen cyclopeeze with the mysis. Just last week, I picked up some of the flake cyclopeeze and use it with the Prime Reef flakes. The only "greens" he's getting is in the Formula 1 pellets. I've often wondered if he needs more "green" food, but he devours everything and has always been healthy and growing really well.
Regarding too much flow, I started out with too much. I had a nice chaotic pattern going and didn't have any quiet spots. Even my caves were getting blasted. I removed one powerhead, and now have about 10x turnover - neglecting skimmer flow. Everything seems fine. Just use some common sense when judging your flow and not just go by the numbers like I initially did. If it seems like your fish can't find a quiet place to call home, then you've probably got too much flow. And remember... if you're going to have multiple fish, you need multiple "homes!"