how do you 'steal' a pokemon? (I am assuming that you need the cheat device to steal another trainers pokemon)
If you are given (stolen) a pokemon that is not of the types listed (exaple: one of the element monkies) you can use it until it faints?
Why only those types listed?
Ty in advance
To steal a Pokemon you would need a cheating device such as Action Replay.
That's up to the player; if you treat it as a stolen Pokemon, you can use it until it faints. If you don't, then you can't use it.
Those are the types traditionally used by the teams; the more evil-seeming Pokemon, as it were, or at least the types commonly seen used by Team Rocket. Ground is included because Giovanni runs the ground-type gym in Viridian City.
@ bwburke94: Wobbuffet, while not listed on the types, is associated with TR enough to allow it, but preferably if the player uses the name "Jessie."