? from beginner

Hello, I sent these questions to Chris Scharpf and he suggested that I send
them to the entire list so here goes:

1)Will the greenside darters and sculpins eat anything except   live foods?
 I have only been able to get them to take, tiny earthworms, black worms,
brine shrimp, and various nymphs I have caught(tedious).

2)Will a yellow bullhead become aggressive (i.e. eat) toward the smaller fish
as he gets larger?  Right now about 4"-5" and growing rapidly.

3)Will crayfish bother other fish in the tank?  I saw a note somewhere that
said they will attempt to catch fish during the night.

4)Will red breastsunfish and/or rock bass coexist with anything else?  All
individuals that I have tried are very nasty to each other and any other
species in the tank(75 gal)

5)Any suggestions for catching madtoms?

Thanks. Dave Hough