Alright, I have even a more advanced version of the bug...
I am on my second file and am sitting at lvl 1( faster leveling/scaling with certain skills) with many skills above 70 so no I do not want to reset this game..
My brynfag is sitting in the market repeating, " I have something to tell you all, Gather round everyone, No need to push and shove." He is in his thieves guild outfit. I have cleared the ratway and tried the flagon which he will not got to.
My understanding of what went wrong, I stole from every container and person before starting this quest. I completed it before he uttered anything about snow elves or started the dialogue. I am upset mainly because of the time investment and the fact that this file was made to fix another bug preventing me from getting the completion of the Theives Guild achievement. I do remember in oblivion having similar problems from guild clashing and infinite loops but noting this severe and well game changing. I have started the Dark Brotherhood before this but only the first quests to get the armor.
To fix this , I do not have any saves... to start off, I have attempted to lure bryn to the ratway. I have pick pocketed those all stuck in the loop of his "gather round" dialogue until getting caught. I tried killing everyone and downing Bryn/Maven.
My next solution would be a mass frenzy/calm but I dont feel like running around setting that up so after reading I felt obliged to post.
I really do like this game and I am only bitter about the time invested, like 4 hours..