Opening Mistakes........
Wouldn't that be the same as playing the French exchange as white?
In your example if black plays 3.d5 then you are playing the French Exchange by a different order of moves. You are not a tempo up on normal lines. It is difficult for white to prove any advantage in this line other than the normal one ply advantage arising out of moving first.
Crash
we have to talk about couple of white's moves. White has no aim no strategy to improve its game. on other hand black has enough game knowledge to punish white's aimless. IF YOU HAVE NO STRATEGY YOU CAN NOT WIN THE GAME.
Don't make opening mistakes.