About the Ruy Lopez--
4. Bxc6 normally doesn't win a pawn: play typically continues with 4... dxc6, after which if you play 5. Nxe5 black then has 5... Qd4, forking the pawn and knight.
6. d4: once again, don't assume that you'll remain up a pawn, as black can play 6... d6 7. Nf3 Qxe4+, regaining the pawn with a tempo. Since black failed to do this, you should have played Nc3 on your seventh move in order to hold on to your extra pawn.
i did learn something from this tournament. theme tournaments are a lot harder than i expected if it's an opening that you're not completely comfortable with. i should have known ;)
any comments are greatly appreciated.