"1. to waste time to drive the Bishop away,that he cant take this Knight.
Not true. The moves a3 and b4 go with tempo, as the bishop has to move as well. In fact this very bishop is the main target of White's strategy."Well,in my opinion white has to waste time.Of course he drives the Bishop away with tempo.However the Bishop wanted to go to b6 anyway and black had to waste two tempos to do that.By pushing him away white waste time to help black with his plan.
That was in fact my general idea.
I would like to stop analyzing the Bf4 line,because it is impossible to analyze all the variations.By the way we are searching now on move 17.!
I think it is much better to know ideas instead of moves.
I would really like to start analyzing 4.Nf3 now,if everybody agree.
There is a way for black to build up an attak.
Eg.
1. d4 Nf6 2. c4 e5 3. dxe5 Ng4 4. Nf3 Bc5 5. e3 Nc6 6.Be2 Ngxe5 7. Nxe5 Nxe5 8. O-O O-O 9. Nc3 Re8 10. b3 a5 11. Bb2 Ra6
I have analyzed this a lot and it seems,that black has more chances to win.However there is a line with Qd5+Ne4 where white can equalize or maybe get a slight advantage.
But actually I want to analyze the very annoying
10.Ne4Suddanly black has to move his bishop to an unpleasent position and ,if black wants to play the plan a5,Ra6,Rh6 there is the move
c4-c5,which makes sure that black cannot play Ra6.
If there will be no way tio attak on the KS ,black will have a bad position.So I really need some new ideas here,otherwise this variation will force me some time to quit the Bpg.