They seem to be gentle with the others, especially with the eel how she just moved him out of the way. I wish I had a separate tank to put them in. I feed them Veggie pellets, night crawlers and Hikari pellets.
Mine would eat any plant down to nubs, and chew on wood.
They consumed the papyrus, which is like cardboard from a 3ft plant down to nothing.
If you want eggs and fry, might be a good idea to remove some of your more nocturnal feeders.
I would imagine that though they are fairly calm now, once fry appear, an attitude adjustment may be in the offing.
I found by feeding lots of leafy greens, like dandelions or romaine, they would take that instead of the wood.