5. g4 avoids the slaughter.

I think here it should go something like the Muzio gambit, with an extra move for white and an awkward pawn for black. SO after those moves, it should go:

d4 g5

Bc4 d6 (stop access for Ne5)

Nc3 g4

Bxf4 gxf3

Qxf3. After this, once white castles, theres a really nice attack on f7

This opening looks like a loser according to the stats from the games in the database.