Do i need to do the fishing quest to get the thieves guild back to power cuz im stuck on pickpocketing Aela the huntress cuz the item i need to get off her has a 0% chance to be stolen and i dont want to put anything in or lvl pickpocking?

You can go back to Vex/Delvin, cancel the job, and get another one.

EDIT: If you don't want to level pickpocketing, why take a fishing job?

^This.....I had a particularly nasty pickpocketing mission to get my final job in markarth....I just quit that one with Delvin and got another one. You might have to do that a few times in order to get a job back in the city you want that isn't fishing jobs.

ok thanks

I had the problem with getting Torsten Cruel-Sea's Gold Ruby Necklace, zero % chance despite being level 42, having a couple of perks, several skill boosting bits of apparel and drinking a potion. I guess I'll have to get another quest too.

I don't believe that you need to do the fishing jobs in order to restore the Thieves Guild (and for the achievement), you can take any of the jobs but will have to do at least 5 jobs in each city to get the Achievement.

yeah 5 small jobs in each city (besides riften)
to get the 4 special jobs
The special jobs are pretty easy except the Markarth one takes a while.
After you do those 4 you get the achievement/guild master