So I finished the thieves guilde/nightingale quest line but brynjolf wont talk to me he is to busy.

I can get lots of little quests still from vex and devlin.

Is it worth doing those little quests? Am I 'member' of the thieves guild yet?

those "Jobs" you do for Vex abd Dev lead to special jobs to solidify the guilds position in one of five given cities. Once you complete that you become master of the guild. five jobs per city is required to unlock the special job. so try keep track of how many u have done in each city..good luck. there is also the stones of barenziah quest. what is it?24 stones?