Also, this may sound dumb, but make sure you can recognize and defend against the 4 move checkmate.

Question--why do you want to survive longer against better players?

Why not just play and learn from your mistakes?  Instead of trying to prolong a game--why not try and make each of your moves the best move possible?

Just looked up the hedgehog and stonewall. It seems to me, that those aply to players playing black. I´m playing white.

@ ponz111: I see your point, but in this single game the focus ist to survive as long as possible.

@AdvLegitimate and all other advaced players: Besides being very tactical, will trying the "evans gambit" bring me in a bad starting position concerning the focus of surviving long? (I´m asking, cause I spend some time on this now and see that as lost time, if I switch to another strategy now.)