Attending multiple regionals

[SenorZ]

Had a hard time finding info about this topic, so I apologize if this has "been covered."

Questions:
1. In how many regional competitions may a team actually compete?
2. If a team qualifies for the finals at one regional, do they still compete at the others they have registered for?

Call me crazy but I think it would be unfair if, say, four or five strong teams enter regional competitions near their "home" regional, and squeeze out less strong teams, even if it is allowed.
I understand the need for practice and working out the kinks, but it seems a bit elitist.

This has been sticking in my brain after seeing many shipping containers at the LA regional which were shipped directly from the San Diego regional.