i have one in a 55 gallon tank and when everyone says that they will eat anything that fits in their mouth, its not an exaggeration. I love mine, however i will say that its hard to know if anything else is getting any food because it seems to eat non-stop.
All the research I've done into them says that in captivity, 12" is to be expected but not much larger, so a 55 is probably the smallest non-breeder tank possible. As for escaping, I personally have not experienced it however when something disturbs or irritates him he does shoot up and down the tank. Never jumping just using the entirety of the space given to him, however i wouldn't take a chance with any eel shaped fish because they need very little space to escape