Preparing to get a better player: Championpool! what do you think?

So after s2 ended i did pretty well on a few champs I enjoyed but wasnt able to climb up in ELO and still im very weak on some roles. For s3 i decided to actually get a better player befor doing my placementmatches and started by getting it down with my championpool.

So i analyzed my current pool and dumped it right away. My plan for s3 is to get my hand on a selection of champions that can cover a whide variety of different types of champions (assasin, tank, farmer, splitpush...). I created a new pool of champs and I would like to hear what the school thinks of it. The idear is to play at least 10 matches with every champ in normalQ to get the basics down before I jump into ranked. (Champs marked with an "X" are champs i allready know really good and transfered out of my old pool)

Support:

• Sona
• Taric (X)
• Leona (X)

Here i got a aggressive support with Leona and a ranged/sustain with Sona. I feel pretty well on Taric and he is somewhere between this two so i picked him up. Not sure about Nunu... i dont like him that much and i feel he is not that strong in soloQ.

AD-Carry:

• Tristana
• Corki
• Vayne

Here we have a lategame powerhouse with Tristana and i just love her. Corki feels pretty good and Vayne is a hypercarry, so i think i got a ok collection here. Im a little concerned about Ezrael because he is so strong right now. I never touched him and i dont want i guess but maybe i have to?

Mid:

• (Vlad)
• Diana
• Oriana
• Twisted Fate
• Morgana (x)

Mid was the first role i ever played and i really like it, but atm i focus more on other roles... Here i have a overall good champ with oriana, a assassin with diana, Splitpush with TF (although he is one of the hardest champs to play imo) and a farmer with morgana.

Top:

• Vlad
• Riven (x)
• Jax
• Shen

Top is a role i picked up a lil while ago and i do ok on it i guess. I play a lot of riven but i feel that i really need to buff it up, so i picked up shen as Splitpush/tank, Jax as a heavy bruiser and Vlad as a general ranged champ cause i feel i often get outplayed by some meeles like garen when i play riven/Jax.

Jungle:

• Mundo
• Nocturne
• Amumu
• (Shen)

So on the jungle... im not 100% sure with this setup cause of the junglechanges comming in but i guess i got a good bunch of the t1 junglers in. Maybe i switch Nocturne with Lee Sin or pick him up Later since he is pretty strong overall imo.

WEEEEEE wall of text ;) let me know what you think of it. Do i lag some importend roles?