I spend the better part of yesterday and today figuring this one out but I'm glad it's finally done. Thank God for Google!
This will address several issues:
Taking Care of Business Script issue
Loud and Clear Script issue
Script errors in thieves Guild
Sound Errors in Cornered Rat
First I want to point out that a lot of the errors most people seem to be encountering stem from one source in particular (theory not a fact)...The archived file system. If you have ever peered into the file structure for Skyrim (I am using Skyrim Via Steam) it packages all of the data into nice big bsa files. While a general practice when dealing with a game that has 6+GB of files, it could be a burden when archiving on the fly. How does the end-user suffering bugs and glitches resolve this issue? Unpack the svcker! (fix 1)
Bug Fix: Open youre skyrim /Data folder. Go to this http://www.tesnexus.com/downloads/file.php?id=3117. Extract the .rar file in youre /data folder. Open the program and "extract all" Skyrim - Voicesixtra.bsa. It will make a new Sound folder in youre /data. Restart the game and do the quest again. Esbern will now be able to talk to you and you can carry on with the game! Hope this helped!

iamond:
example file location: D:\Program Files (x86)\Steam\steamapps\common\skyrim\Data
Thank You Nameless Freak!
Use the Same utility for Skyrim - Misc.bsa for script issues such as the Loud and Clear.
Once the files are extracted in the data folder, you MUST restart the game for it to process the unarchived files.
Conditional Retroactive Console Commands once files are unarchived:
To fix a blundering Brynjolf who thinks he still needs to make a scene long after the quest was complete use this command (fix 2):
clearquestaliases TG00SP
If You are somewhere stuck between Taking Care of Business and Loud and Clear where Brynjolf just says hmm in the flagon use this command (fix 3):
setstage TG01 200
Brynjolf should proceed down to the Ragged Flagon afterwards. If he doesn't and still wants to hang around topside use the following command (fix 4) while in the Ragged Flagon:
prid 00020545 disable resurrect 1 enable moveto player
Hope this helps, sure saved me 50 hours of replay and a long winded email thread with Tech support!
Specs:
Windows 7 x64
Steam Version
Credits/Sources:
See http://elderscrolls.wikia.com/wiki/A_Cornered_Rat and http://www.minecraftforum.net/topic/786124-skyrim-a-cornered-rat-bug-fix/ for unpacker fix 1
see http://www.uesp.net/wiki/Skyrim:A_Chance_Arrangement for fix 2
See http://www.uesp.net/wiki/Skyrim:Taking_Care_of_Business for fix 3 and 4