Thanks for replying chevalier
Well let's see...
a) 7. Bg5 doesn't look so annoying to me though of course I might be wrong.. I'd say 7... Nbd7 and then
i) if white plays e3 cutting the bishop retreat, play h6 and force bishop to stay on h4 and proceed with a b6,bb7,c5 plan
ii) Otherwise, proceed with the e5 plan, just like in the other variations
b) Yes of course white can play 5.nc3 and 5.a3.. I didn't say "Complete repertoire" or something

I'm planning to cover other lines too, but wanted to get some opinions first
c) Black can do many things against 6.Nc3!? that's for sure, but I wanted to find a shortcut to a comfortable middlegame and exchanging twice on c3 almost by force, retaining the light-squared bishops on the board and then blockading the whole center with 11...e5, 12.d5 on dark squares seemed a good idea
d) Yes that's a critical line..
11. Ne1 a5, 12. Nd3 Na6, 13. f4
I don't think I like 13...c6 so much. I have to take a look on that one..
Maybe a Nfd7, Nac5, getting one pair of knight off the board, and outposting the remaining black one on c5, provoking b4 is one idea..
Trying to make use of the fact that 13.f4 weakens the 'g4' square might be another one..
But in general I like the center to stay blocked because with the center blocked and the black bishop staying on c8-a3 diagonal, white's Bg2 is a nice piece of furniture