Hi Zatara, I won't touch 5. Qg4 if I were you. At first it seems like some sort of a dream variation: very sharp but with hardly any theory. Shocked and ready to defend my beloved French, I did some analysis and happily concluded that it is only for dare devils to play in club evenings. I suggest you investigate after his supposed solution of 11.Be3: Black's play can be improved, after which one finds that 11. Be3 merely saves White from immediate disaster but no more. Black has the advantage in the long run. 

As for the Two Knights' variation, 
After...
1. e4 e6
2.Nf3 d5
3. Nc3 Nf6
4. e5 Nfd7
5. d4 c5
6. dxc5 Bxc5
7. Bd3 Nc6
8. Bf4, 
Black can play ...f7-f6 which equalizes comfortably for Black at the very least, and may actually give the second player a slight advantage...though the position is strictly speaking, dynamically balanced. I suppose at least all results are still open on the table and ultimately, the better player should win from here with either colour.

Vive le Français!!