UU/NU Semi-Rain Dancing Team

I'm extemely incredibly awfully dreadfully and extraordinarily new to competitive battling and everything associated with it (such as breeding, ev's, etc). I usually just play the games as it is and breed for baby pokemon ... heh. I'm just wondering if this team is even possible (made it on smogon) to create in a pokemon game + would it do well in competitive battling?

Lead-Screens/Stealth Rock
Corsola (Corale)
Nature: Lax
Ability: Natural Cure
Item: Light Clay
EV Spread (?): 255 HP/ 255 Speed
Moveset: Stealth Rock, Reflect, Light Screen, and Mirror Coat
Used to create the most sturdiest defenses for my team since it's mainly a mixture of pokemon weak to special atk and physical atk moves. Stealth rock is an obvious choice and Mirror Coat is there 'cause of low speed and mediocre special defense. Equaling in some decent damage on a special sweeper. Light clay is to lengthen my teams defenses.

Rain Dancer #1/Tanker
Quagsire (Neo)
Nature: Careful
Ability: Water Absorb
Item: Damp Rock
EV Spread: 255 Attack / 255 Speed
Moveset: Rain Dance, Recover, Stockpile, Waterfall
Used to dance very smexishly in return for rain. Doubling it's speed and coupled with it's very nice attack stat equals in good damage with Waterfall + bonus for flinchax. Stockpile for defense and Recover for emergencies.

Rain Dancer #2/Special Sweeper/Healer
Ampharos (Shiny)
Nature: Lax
Ability: Static
Item: Damp Rock
EV Spread: 255 Speed / 255 Special Attack
Moveset: Rain Dance, Thunder, Heal Bell, and Focus Blast
Rain Dance/Thunder for 100% STAB accuracy. Heal Bell for annoyers and Focus Blast to deal with ground-types.

Special Sweeper/Minor Annoyer
Grumpig (Fortune)
Nature: Modest
Ability: Thick Fat
Item: Mystic Water
EV Spread: 255 Speed / 255 Special Attack
Moveset: Calm Mind, Psychic, Hidden Power (Water), and Toxic
Wither away enemies with Toxic and use Calm Mind to boost up already awesome special stats. Psychic for stab and Hidden Power/Calm Mind/Rain Dance for epic lulz.

Special Sweeper
Mantine (Radio)
Nature: Quiet
Ability: Swift Swim
Item: Leftovers
EV Spread: 252 HP / 252 Defense
Moveset: Aqua Ring, Surf, Ice Beam, and Twister
Aqua Ring for self-healing and Surf for STAB. Ice Beam to deal with Grass and Twister/Ice Beam to deal with Dragon Types. Twister also makes an epic Mantine.

Physical Sweeper (FINALLY!)
Relicanth (Hurricane)
Nature: Adamant
Ability: Rock Head
Item: Life Orb
EV Spread: 252 Spd / 252 Special Defense
Moveset: Waterfall, Head Smash, Earthquake, and Double-Edge
Two powerful recoil moves on this guy? Rock head takes care of that. Waterfall and Earthquake for STAB.

Comments, suggestions, (flames), and is this a possible team to create in-game?

For Grumpig, you should use Life Orb since it provides a much better power increase than Mystic water iirc.

Never use 255 EVs on anything. For each 4 EVs, you gain one extra stat point. 255 =/= divisible by 4. Put 252 on both main stats, and 4 on something else you could use(usually HP)

Sometimes you do not even need all 252...240 will do it then you can have a more balanced poke every 4 Evs is one stat point

Relicanth doesn't get STAB from EQuake, he's Water/Rock. I'd also suggest giving Quagsire more HP EVs, hes better built for that.

Bump!

It's been a long time and I still need more critiques. :c