I feel a little stupid asking a question about my (former) hometown, but the fact is that GRU was always my final destination; it'll be my first time actually connecting there.

My itinerary is:
SFO-ATL-GRU with DL in F/C
3 hours layover in GRU (if all goes well!)
GRU-REC (that's Recife) with Gol
I'll be on 2 separate tickets.

Questions:
Would DL check my luggage all the way through?
Do I have to retrieve my luggage and go through customs? If yes, where do I give it back?
Will I have issues with luggage weight? DL allows me 2 x 70 lb and Gol is probably on the piece concept.
I'm planning on online check-in for the Gol flight (probably at the DL lounge in ATL).

Maria