Because after one century of grandmaster practice the consensus is that black has full compensation for the pawn in your final position due to his quick development, open lines and space advantage (after Be2 h6 Nf3 e4).
Black can also play B(c)5 which is less risky and completely satisfactory, not not even remotely as ambitious as Nf6. It's a matter of style and taste.
What he said.
Nf6 is "Two Knights" and it's been played successfully for a long time. The line you've shown is common enough although not the only line available to black (or white). I have a game on the go right now where we went down the path you've shown, and in the position given I played Qf3 to pin the rook, and black played Bb7 to upin everything. Pretty even game now, but black has had good counterplay for his money, that's for sure.
Because Bd5 is illegal. 3...Nf6 isn't duboius it's as mainstream as it comes. Now 1.e4,c5 2.b4?! is an example of a dubious opening because 2...cxb4 3.a3,d5! and at the very least black equalized, and has some traps involving winning the a1 rook, but those can be avoided if white knows what he's doing.
1.d4,e5? is simply bad, either fishing for cheap tactical tricks or entering a game that feels like an e4 game but where black can't castle due to Bc4 (talking about the 2.dxe5,f6 3.e4,Nc6 4.Nf3,fxe5 5.Bc4 line here)
In short, you could do much worse than a mainline opening that stood the test of time.
sorry. meant Bc5.
If I knew for sure that white would play 5...Nxd5 6.Nxf7?!, then I would most probably prefer it over 5...Na5.
And, if you don't like your pawn structure "being a mess" then 5...Na5 6.Bb5+ Bd7 is perfectly playable and adequate.
Amen.
The Fried Liver scores well for White because Black does not defend well. If you cook it correctly and fry some onions alongside, fried liver is quite tasty!
In the Italian game, what exactly is the point of 3... Nf6 See illustration below:
Instead, why shouldn't black do 3... Bd5