Questions about breeding and trading in B/W

[firebrand164]

I'm trying to plan a team for Black/White, and was hoping you guys could help me out with a couple of questions that will affect my choices.

1) When's the earliest you can breed? I know the Daycare's on Route 3, but apparently you can only put one Pokemon in to begin with.
2) Can you still trade eggs?
3) Can people trade you Pokemon from earlier generations before you beat the Elite 4?

Thanks in advance!