Yes, 0-0-0 is clearly bad. With your having played a6, and white having a3 in already, its just way to easy for white to make progress. Nf7 would likely be a ton better.
White deviates first from sound play with 7. be3. Only played once in the database at http://www.365chess.com/opening.php?m=13&n=4461&ms=e4.e6.d4.d5.e5.c5.c3.Nc6.Nf3.Bd7.a3.f6&ns=3.16.12.17.453.525.454.526.711.1250.1178.4461. I think the expert who won that game as black had the right idea w/ p(f) x p. Alternatively, c4 is played by black a lot at move 6 (instead of f6) and can only be stronger after white has committed the bishop to be3. Taking with the cpawn instead seems inferior because it helps white's congestion and might result in be3 actually being a useful developing move (whereas its clearly not after after c4).
Here is an interesting 15'+10" game that i played today here on Chess.com. I'm Black and as i always do also OTB i play the French Defense. White chooses the Advance Variation with the interesting line 6. a3, followed by the rare 7. Be3,