From my experience with WoW and what little I had with the Beta, these mean simply:
PvE: These are servers that typically focus on PvE. This means that in the zones you quest in, if you find a character of the other faction, you cannot kill them, unless they are 'flagged' for PvP. You can still do the PvP that requires queuing, which is what I believe you are asking about (I forget what they call it in SWtOR, in WoW it was Battlegrounds.) EDIT: Warzones. They're called Warzones.
PvP: These are servers that focus on PvP. This means that while questing in most areas, you can fight and kill any opposing faction member you wish. Flashpoints are still available like they are in PvE servers.
RPPvP and RPPvE: These are servers that are either PvE or PvP with a more specialized community. The idea is that you aren't playing a character, you ARE that character. You don't have to, but the community on these servers ideally like to focus on Role Playing aspects.
EDIT: As for the region thing, it doesn't matter, but I believe on in your region will typically be faster to play on, and more likely to include people where you live.