Channel cats are not nocturnal in my experience. They are always out and about, and gobbling up anything in sight. The last thing you want, is to speed up growth, though!
They are quite non-fussy when it comes to foods, as the guys stated above. I'd stay away from live feeders altogether. Beef heart is also unnecessary as it requires preparation (all visible fat removal). Catfish pellets, koi pellets, gamefish pellets are all taken eagerly, sinking or floating. Fish (whole or pieces), shrimp, mussel, any kind of sea food are eagerly consumed.
Freezing kills all parasites. It does not kill bacteria.
They will hide mostly while small. They will come out for food if hungry. They will start coming out more as they grow in size and, hence, in confidence. They grow extremely quickly, putting on 0.5 lb of body mass per every 1 lb of food. Mine latest ones were 5" last May. They are 1.5' about 5 lb. And this is far from champion growth.
here is everything I feed/fed mine:
1: hikari carnivore
2: NLS pellets
3: beef heart
4: bloodworms
5: plankton
6: market shrimp
7: ghost shrimp
8: tilapia
9: red belly pacu
10: live fish
11: crawfish
12: earth worms
first pic is of him in february 2012 in his 10 gallon tank at 3". second pic is of him in his 75 gallon tank at 10" long. I've got almost 2" a month growth rate on him from this. i feed at least twice a day when he was little and now i feed once a day. also he is a male and his name is dizzy