White has a slight advantage in the Accepted line, but it will depend what level you play at.  Even at the higher levels both Anand and Kasparov have played it.

You give up the center in the QGA as black, but white has an isolated Queen's pawn to deal with.  There are too many alternatives for the QGA to go over them all here.

In general, white is taking the center, and hopes that his advantage will compensate for the pawn.  A very logical move then is 3. e4, grabbing the center with a pawn duo, though 3. Nf3 has been more popular.

If Black tries to hard to keep the pawn, he'll only hurt himself.