Pawn and Two: <keypusher> Tarrasch made several comments, but did not include any variations. I will include just a few of Tarrasch's comments.
After 12.Qb3, Tarrasch stated: <White begins an attack against Black's center, with this move and the following moves and up to a certain point White plays the game flawlessly.>
After 21.e5, <White keeps the e6-pawn backwards and he should now be able to get the better game.>
After 22.Nd4, <This keeps the e-pawn under fire. White now has a very free position and Black's position remains cramped.>
After 23.Re4, <White wants to move the other Rook to the d-file. Much better however was 23.Re2, as we will soon see.>
After 31.Qd4, <This will cost the exchange.>
I did a review of the game using Fritz 10. Fritz confirms that Black has a very difficult game after the opening. However, I did not find a decisive winning line for White.
As you have noted, Fritz did prefer 11.b5 Na5 12.Bxa7 Rxa7, but again nothing decisive.
At move 16, Fritz preferred 16.fxe5 dxe5 (1.01) (18 ply) 17.Nf2 Nf7 18.Nd2 Raa8 19.Nf3 Rad8 20.Rad1. White has a nice position, but I did not find a decisive continuation.
At move 21, Fritz preferred 21.cxd4 (1.04) (17 ply) 21...e5 22.Nf2 Ng4 23.Nxg4 Qxg4 24.dxe5 Rae8 25.Qd5. Again, White has a nice position, but I did not find a winning continuation.
At move 23, Walbrodt's 23.Re4 is a better move than Tarrasch's suggestion of 23.Re2.
Here is a comparsion of continuations at move 23: (.50) (17 ply) 23.Re4 Qe7 24.Qc2 Kg8 25.Rf3 c5 26.bxc5 Qxc5; (.35) (17 ply) 23.Re2 Nd8 24.Rd1 Nc6 25.c4 Nf4 26.Nxf4 Rxf4; and (.76) (17 ply) 23.Nf2 Nf4 23.Qd1 Kh8 25.Qd2 Ng6 26.Nd3 Ng5.
At move 31, White still had equality. Fritz found 4 moves that gave White evaluations of .03 to .15 at 17 ply. These moves are 31.Nxd5; 31.Ne2 31.Kh1 and 31.Ra1.
Perhaps with a deeper or better search someone will find a convincing winning line for White. However, I did not find one, and based on Tarrasch's notes, neither did he.