Blastoise is far too bulky and slow to have maximum speed EV's. Blance out it's defencive EV's and 252 in Attack or Sp.Attack, or even balance them out and make it mixed. I would use:
Blastoise@Leftovers
120 Sp.Defense 120 Defense 80 Attack 120 Sp.Attack
Quiet/Brave
Haze
Ice Beam
Surf
Earthquake
No, sorry. Blastoise is one of my favorite pokemon, I have plenty of experience with the shell dude. If you aren't gonna max blastoise's HP, don't use it. Just don't. You will be brutally destroyed by powerful tanks and sweepers. Earthquake is lol on blastoise. sorry, no STAB and you shouldn't be staying in against powerful electric types anyways.
Haze is a nice move for it since sweepers and tanks like curselax can't blindly power up in front of its face and OHKO it.
Blastoise pretty much needs surf since you won't be investing much in SAtk or Atk, or you SHOULDN'T be anyways...and its ability helps it a lot.
Blastoise's power to its full extent? What power? It can't attack very well, that's what swampert is for. Blastoise was made to spin...
Ice beam, yawn, and rest are good ideas for the last slot. I prefer rest since I have blissey w/ aromatherapy, but that's just me. Ice beam works well too, since you might need to duke it out with mence or other dragons. Counter and mirror coat are other options, but require a lot of prediction and probably rest or wish support as well.
Sorry, using blastoise as an attacker is mere novelty...it hardly gets by as a defensive poke.