Advice?

[Noscreenname]

I need some help deciding what to do with my team, here they are so far (plus some moves I plan to teach Gengar):

Gengar (Bold) @Focus band
EVs: Mostly HP, with many more in speed and some in Defense and Special Defense
-Focus Blast
-Hypnosis
-Shadow ball
-Thunderbolt

Torterra (careful) @Razor claw
EVs: no clue, I got it way before I knew about the things.
-Earthquake
-Leech seed
-Wood hammer
-Stone edge

Lucario (Bold) @Leftovers
EVs: Mostly HP again, with some speed and defense.
-Close combat
-Aura sphere
-Toxic
-Flash cannon

Charizard (Quirky) @Charcoal
EVs: again, no idea.
-Flamethrower
-Sunny day
-Solarbeam
-Fly

Gyarados (Naive) @Wave incense
EVs: again, don't know.
-Earthquake
-Ice fang
-Surf
-Aqua tail

Magnezone (Hardy) @Magnet
EVs: some in speed, don't know the rest.
-Thunder
-Discharge
-Mirror shot
-Magnet rise

Some notes:
--Gengar currently knows Sludge bomb and Confuse ray, to be replaced soon by Thunderbolt and Focus blast since it's been suggested so much.
--I would especially like advice on hold items.
--Gyarados really only knows Surf for its value outside of battles, so ideas for a replacement move would be nice.
--No, I am not going to get a whole new pokemon of the same species just to get the right nature.
--Toxic is there for Lucario because he once knew Dragon pulse, which was pointless, and I couldn't think of anything more useful to replace it with.

Some misc. questions:
--Does leech seed ever wear off, or does it last the entire battle?
--When teams are put at level 100 for wifi battling, are EVs and IVs part of the calculation?

Help would be nice, as I've lost a lot of battles on Wifi so far.

 

[Arbok]

Some misc. questions:
--Does leech seed ever wear off, or does it last the entire battle?
--When teams are put at level 100 for wifi battling, are EVs and IVs part of the calculation?

1. No. Only when the 'Leech Seeded' Pokémon gets killed.
2. I don't think so, the Pokémon game can't choose to add EV's.