In live poker, most players are always looking for an edge, and several have no scruples about bending the rules. I mentioned collusion before. This can take various forms and may or not include the dealer. Marking cards or stealing chips are other techniques commonly used. Poker players can easily list several more scams that they must be constantly vigilant about.
Tournaments abound in both games.
This is true of most things in life. The more you put into it, the more you get out of it. It depends upon the player. Computer nerds will do better at video poker. People people will do better at regular poker.