Team Ying [Advice Needed!]

Alright, well this team is the one I've used for the storyline and such, but I'm debating as to whether or not to reproduce it again with better natures, IVs (Via Ditto), and actually EV train them for competitive play. I'd appreciate any help with move sets, held items, natures, and EV spreads you all can offer. Thanks in advance!

#1. Lilligant [Own Tempo]
Modest
Moveset:
HP (Water)
Sleep Power
Quiver Dance
Petal Dance

#2. Hydregion [Levitate]
Modest
Moveset:
Fire Blast
Dark Pulse
Draco Meteor
Surf

#3. Eelektross [Levitate]
Lonely
Moveset:
Rock Slide
Wild Charge/Zap Cannon
Dragon Claw
Flamethrower

#4. Vanilluxe [Ice Body]
Modest
Moveset:
Automize
Blizzard
Hail
Flash Cannon

OR

#4. Mienshao [Inner Focus/Regenerator]
Adamant
Moveset:
Hi-Jump Kick
U-Turn/Poison Jab
Stone Edge
Aerial Ace

#5. Jellicent [Cursed Body]
Calm
Moveset:
Sludge Wave
Hydro Pump
Shadow Ball
Psychic/Acid Armor

#6. Volcarona
Modest
Moveset:
Quiver Dance
Hurricane
Fire Blast
Bug Buzz

Any help would be greatly appreciated!

Items:
Lilligant (Leftovers/Life Orb)
Hydreigon (Choice Scarf/Choice Specs)
Mienshao (Life Orb)
Jellicent (Leftovers)
Volcarona (Life Orb)

On to the EVs and moves:
Make Hydreigon's and Lillgant's EV spread 4 HP/252 SAtk/252 Spe

Make Eelektross' EV spread with: 252 Atk/208 SAtk/48 Spe

Give Mienshao this set:
-Fake Out
-Hi Jump Kick
-Stone Edge
-U-turn
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Life Orb
Ability: Regeneration

Jellicent shouldn't have Cursed Body. It's also better with this:
-Scald/Surf
-Will-o-Wisp/Toxic
-Recover
-Shadow Ball/Ice Beam/Taunt
Nature: Bold/Calm
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers
Ability: Water Absorb

Volcarona should be Timid. Psychic or Hidden Power (Rock/Ground) is an option over Hurricane.