I've fished on trotlines for 40 years. Not exclusively, but I've used them for that long. I generally fish for catfish, any species, but I love to target flathead with live bait. I usually use goldfish or crawfish. I've caught channel and blue catfish on worms, crawfish, cheese, cut shad, hot dogs, and gold fish. I've also caught Gar, Drum, paddle fish, eels, buffalo and lots of catfish. I've never once caught a bass, crappie, bream, or striper. I wouldn't worry about catching gamefish. My experience is it doesn't happen.
I put out my lines late in the afternoon and check them in the morning. When left out during the day I generally catch some non-targeted fish like Gar and Drum. Not that they're bad, just not what I'm after. Both Gar and Drum are good to eat, just takes a bit more work to clean.