They will uproot plants because the dig little tunnels to live in, its quite amazing to watch them digging, they make a little 'snao plough' with their claws.
As for feeding they will eat most things, I feed mine Tetra variety wafers, catfish pellets and of course King prawns (once every 3-4 days)
Ive never bred them or even tried to, too many horror stories of them attacking eachother when keeping more than one, you'd need lots of space.
I did see a breeding pair for sale in my LFS, they were both about 9" for £40......I was so tempted and would have if I didnt already have the one Ive got.