So i have Edwin in my party but he starts complaining about the reputation but im only at 14 and it's already bothering me. So i think about getting Imoen. The problems are:
-I want to get Carsomyr and FoA before going to Spellhold
-I want Mazzy in my party and the Shadow dragon armour wouldn't be bad too
But to have these i must make or at least begin 4 quests and i have alredy done most of the others so i wonder if she could reach the highest levels (i dont have ToB and have a full party).

You really don't need Shadow Dragon armor for Mazzy. She wears plate mails just nicely.

There is a nice lightweight one available at the conclusion of the drow city plotline. You can also get a nice one in Bodhi's gauntlet.

Oups, i didn't explain it right. This armour is not for Mazzy but for my assassin (right now i wonder if thieves can wear this armour!)

Yeah, it counts as a kind of leather armor (hide armor would be the most logical, but I don't know). Thieves (and kitted rangers) can wear it just nicely.

What quests have you actually done?

Trade Meet
Quest of Bloodscalp
the murder in bridge district
the planar prison
the copper coronet and the "slave boat"
circus tent
Jaheira's, Keldorn's and Cernd's Quests
the thing about the sculpture with the temple
I planed to do Korgan's and Edwin's quests this evening
plus the 4 i'd like to do for equipment (see above)

IIRC, that leaves the unseing eye, the planar sphere, Mazzy's quest (i won't do the other NPCs' quests), the menestrel (quest of Xzar) and some side quests like tusted runes, Kangaxx. And i'd like to do some of these quests too (i like doing all i can before going farther in the chapter).