Response to 4. d3 in 2 Knights defense

I''m the type of player who likes sharp and complicated positions. I play the two knights defense against the Italian in hopes of the following:

But against d3, I get stuck in this really boring game. Is there any line I can play, even unconventional, to spice it up? I'm at 1620 USCF, so I can still get away with stupid but sharp openings.  For some idea, my current repetoire includes (an incomplete list since many don't have names):

White:
Halloween Gambit, Milner-Barry Gambit, Advanced variation in Caro-Kan with 4. Nc3, Austrian Attack against Pirc, Smith-Morra Gambit

Black: Schliemann Defense, Fritz Variation of 2 Knights defensee (as shown above), Albin's Counter-Gambit

So I have no requirement to play something sound. Are there any interesting lines I can try against 4. d3? Even something hidden a few moves in? 

Against 4.d3:

The system with 4...Be7 is at least equally good to 4...Bc5. According to white's replies you may be able to play ...d5 in one go, or go for 0-0, Kh8, Ng8 and ...f5.

This variation is well covered in a recent Everyman book.

Oh... I have played in the (distant) past 5...Nd4 as well as 5...b5 many times with 100% success (these two moves lead to the same main line) but objectively speaking, if White knows his stuff, Black is suffering... 

Is this line somewhat okay? You probably meant d5 to not be played immediately, but this looks like it could be fun. Also, I can't find any games with the sequence 0-0, Kh8, Ng8, f5, although that looks like something I would want to play. Do you know a possible sequence that allows black to play that?

No, this is not OK at all. This is more like a (very) bad variation of the Ruy Marshall. I have played once as Black 8...Qh4, and won in just 16 moves, but objectively 4...d5?! is not very good.

The aforementioned plan with ...Kh8, ...Ng8 etc has been played a few hundreds of times. Last game I cared to mark on that:

Notice the moves 6.Re1 (aimed against ...d7-d5) and 7.a4 (lacking a useful attacking plan, white steals space in the queenside). Both moves are currently considered optimal. Yet, Black never seemd to be in any trouble, and cound possibly avoid massive simplifications and/or repetition in a couple of ways.

What should Black play here?

I got in trouble a few times here, what is a good way to meet d4?

4.c3 is the main line of the Italian, nowadays Black's 4...Nf6 will be answered with 5.d3 and a tense positional battle not unlike the closed Ruy Lopez, as the old 5.d4 seems to promise the second player at least easy equality.

5.c3 is indeed best answered by 5...Nxe4 6.d4 d5.

As to the OP's question: after 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d3 there's no way you can avoid a slower and more positional game.

Considering the rest of your repertoire plus the fact you don't mind playing dubious openings I wonder why you don't consider taking up the Latvian? After 1.e4 e5 2.Nf3 f5 it is you who has decided which kind of battle will take place, although this comes at a price: The Latvian is considered unsound, and with best play from White your defence will be difficult, but then again, with this it should fit with your other openings ;-)

I don't think I'd ever consider taking up this gambit, but then again I'm a much more solid player than you, and it might fit for you.

Yes, Estrinian, your diagram is from the 4.Ng5 mainline of the Two Knights. And how exactly does that fit with the discussion about how to answer White's 4.d3?