I think after d4 white pawn completely capture the center. White will be quite ahead in developing pieces and after Qh4+ and Ke2. White would play Nf3 in future which would win another tempo.Though Its obvious that white cant castle now but you should remember that one check is not the end of the game. Infact black wont be able to give another check even. White king would be quite safe at e2 for some time.

But I dont like to do that because its very dangerous for White.

The King's Gambit Accepted, Fischer Defense

This is the next variation I'm learning from the King's Gambit Accepted:

In my first game of King's gambit, I continued the line above with d4, I thought it was a disastrous move, coz the queen checked me and did quite a disaster in my right flank. But it turns out according to the book openings, it is the second to the best move with 48.78% win for white, over 34.15% win for black. The best move would be Kf2, I have no idea why, the most balanced move would be g3. Further analysis is still needed, coz as a free member I can't explore further bummer...

The King's Gambit Accepted

The first version of the King's Gambit opening I would learn, the moves are: