Rate my competitive team please

Steelix @ leftovers Nature:Impish ability Sturdy
252 def 252hp 6 sp def
Stealth rock
Rock Polish
Explosion
Earthquake
Physical wall, it's a cool poke also.

Blissey @ Leftovers Nature: Bold ability serene grace
252 spatk 252 def 6HP
Calm Mind
Ice beam
T-bolt
Softboiled
Calm mind is there to boost it's SP def mainly, spatk is just a side affect of it. so I gave it I beam and t-bolt, so it could attack aswell.

Garchomp @ life orb Nature:Lonely ability sand veil
252 atk 252 spe 6hp
Crunch
Fire Fang
Dragon Claw
Earthquake
I'll be replacing this with Electivire soon. dunno what it should be though.

Starmie @ Wise Glasses Nature Modest ability illuminate
252SP.atk 252spe 6 hp
Ice beam
T-bolt
Psychic
surf
Standard special sweeper, nuff said.

Breloom @ toxic orb Nature: Jolly ability Poison heal
252 atk 252 spe 6 hp
Facade
Sky uppercut
spore
Seed Bomb
Poison heal is there for heals, and facade for damage of course, should I replace Sky uppercut with T-punch?

Magnazone @ life orb nature Mild ability sturdy
88atk 84spe 84def 252spatk
T-bolt
Signal beam
Explosion
Flash Cannon
Nother sweeper...

This is the team that I currently use, if you can suggest changes for it, that'd be great.

Steelix is great physical wall with it's massive 200 Def base stat. You don't need Rock Polish for it as it's only going to be a wall. It's not going to do anymore than being a wall. It has low SpA, SpD, Spe and below average Atk and HP. I would suggest

Forretress @ Leftovers
252 HP / 4 Def / 252 SpD
Spikes / Toxic Spikes
Rapid Spin
Stealth Rock
Explosion / Payback

Though Steelix > Forretress in terms of Def, Forretress has access to both Spikes (Toxic Spikes) and Stealth Rock.

Also, Zapdos would be better than Magnezone if you want a Special Sweeper.

Zapdos @ Life Orb
252 SpA / 4 Def / 252 Spe
Thunderbolt
Heatwave
Hidden Power Grass / Ice
Roost

You really don't need Calm Mind on Blissey since you have a Special Sweeper in case you don't want Zapdos. You have Magnezone. Blissey as a Cleric would be more than enough for the team. It won't need Aromatherapy because you have Breloom as your status absorber.

RMT Rating

Good job, overall it's pretty good team. If you could post a little description for each Pokémon and what they do, that'd be nice.

alright I'll do that. thanks for the suggestion, I totally forgot about that.

For Starmie, Illuminate does absolutely nothing in battles; replace it with Natural Cure (which cures status if you switch Starmie out). Also, replace Wise Glasses with Life Orb. Water/Electric/Ice provide good coverage already (though you're walled by Lanturn), so Recover or Rapid Spin could go in there instead (the former to regain lost HP and the latter to get rid of entry hazards).

For Breloom, Focus Punch over Sky Uppercut. Since you're putting your opponent to sleep with Spore, they might switch out, or stay in helplessly giving you a free turn to Focus Punch.