You could have started with a tempo with:
- Nf3 Qe7
which threatens Nxc7+ and winning a rook. Continuing with Black's best response:
- ... Qd8
- Bf4 d6
Bf4 adds an attacker to the c7 pawn so d7 is forced. After this has happened, we are left with:
1. d4 e5 2.dxe5 Qe7 3. Nc3 Qxe5 4. Nf3 Qe7 5. Nd5 Qd8 6. Bf4 d6
Black wasted 6 moves basically to trade a pawn and advance the d pawn, which was forced. White however, has developed both Knights and a Bishop. White's development will continue with e4, posting the strong d5 Knight. If Black plays Nf6, then White further develops with Bc4.
1. d4 e5 2.dxe5 Qe7 3. Nc3 Qxe5 4. Nf3 Qe7 5. Nd5 Qd8 6. Bf4 d6 7. e4 Nf6 8. Bc4
Note that Black did not capture White's e4 pawn because though undefended, Black will lose the Knight to a pin with Qe2. If Black tries to defend with f5:
1. d4 e5 2.dxe5 Qe7 3. Nc3 Qxe5 4. Nf3 Qe7 5. Nd5 Qd8 6. Bf4 d6 7. e4 Nf6 8. Bc4 Nxe4 9. Qe2 f5 10. Bg5 Qd7 11. Nd2 Be7 12. Bxe7 c6 13. Nxe4 fxe4 14. Qh5+ g6 15. Nf6+ Kxe7 16. Qg5 Qd8 17. O-O-O Bf5 18. Nxe4+ Kd7 19. Rxd6+
and the Queen is lost as the King can no longer block the Rook from attacking the Queen.
In eight moves (board 2), White has created a tempo, developed all minor pieces, has strong command of the center, and caused Black to be severely underdeveloped. White also has the option to castle King's side and Queen's side if the Queen moves. If Black does blunder (board 3), White's superior position will easily win the game with the right attacks.
Though I agree that the midgame moves are improvements, I believe a strong position and attack in the beginning is much, much better.