I've had my three for a week now, so i'll chime in with what i have learned.
I keep my three in a heavily planted 38Gal tall (24") with a lot of other fish. If you guys think find yours is tough, you should try it in a tank with so many plants you can't even see all your fish at once anymore.
Anyway, none of the fish bother them at all. They don't even pay attention. I even have a female betta in the tank and she doesn't bother the frogs.
They are VERY good at finding food. Sure they can't see well, but they can SMELL well. I've already seen them eating flakes, frozen bloodworms and algea wafers that i put in for the ottos and snails. I even see them eating dead plant leaves before i can take them out. Not sure if that's part of their diet, but they have ingested plant matter.
Like i said before, they are VERY good at hiding. The only time i saw all three at the same time was when i first put them in the tank. Usually i can find 1 after 5 mins of looking. They all have different spot patterns and sizes so i can tell which is which that way i'm sure all three are still ok. Other that that, i really only see 1 at a time, maybe two if i get lucky.
When i feed the fish, i usually sink some food down for the frogs and the betta (she likes to slink along the bottom through the plants trying to eat the convict fry). WHenever a frog is in sight, they always perk up when food is in the tank. If a flake or bloodworm lands within 8" of them they hunt it down like a dog. They are always picking up flakes and stuff in the gravel during the day between meals. I'm not worried about them finding food at all as long as i make sure some hits the gravel.
I have a good cleanup crew. Any food that's on the gravel when lights go out is gone by morning. All my snails keep the tank spotless! Funny thing though, today my large 3" Mystery snail was eating a large flake when one frog came skipping over and stole it from it! I got a kick out of that.