Sheesh, you should start to rely on me for your UU teams :P I'm getting good at rating and coming up with my own sets. Let's go!
BISHARP
I would suggest replacing Leftovers for Life Orb. This will boost his attack moves, plus won't do damage to you with Swords Dance. Also, replace Substitute for Night Slash.
ROTOM-HEAT
A great Fire-type Special sweeper. Good set.
BLASTOISE
Good, but you may want to make him a mixed tank. He's great with the role, as his stats are all about even, except for his over 100 defenses. Here's a good set to take advantage:
Blastoise (M) @ Sitrus Berry
Trait: Torrent
EVs: 124 Atk, 252 Def, 60 SpAtk, 72 SpDef
Relaxed Nature
Rapid Spin
Hydro Pump
Protect
Earthquake
This is a Blastoise more on the offensive side, but you can make it to a perfect tank.
SHAYMIN
Sad Shaymin Sky is higher ranked, as it would've been perfect. You might want to replace Air Slash for Sunny Day for max healing with Synthesis. You have a Special Sweep-healer.
CROBAT
Is this a staller? If so, you have it all wrong. Crobat's not gonna survive a many attacks, so take out Taunt and put in Cross Poison. High critical-hit ratio and a chance to poison. Or Toxic, if you want.
SNORLAX
No no no no no, this set is of NO USE to you. We'll make him a full-on annoyer.
Snorlax (F) @ Leftovers
Trait: Thick Fat
EVs: 252 HP, 248 Def, 8 SpDef
Careful Nature
Rest
Sleep Talk
Thunder Wave
Whirlwind
There you go. Annoying Snorlax for the win! Woohoo!
I enjoyed rating your team Mew :3. Hope I can do it again :)