I fenced over 1100 gold worth of goods in one fel swoop back when i could. That brought me to here - I've done the arrow of extrication quest, but now it is telling me to wait until the Grey Fox contacts me. Well, I've obviously fenced far more than 800 gold, but I have sat around in just about every city for several days waiting for someone to contact me. What happened?

It sounds like you have run into a known bug with the quest Independent Thievery. What we know about it is detailed here: http://www.uesp.net/wiki/Oblivion:Thieves_Guild#Bugs

First time I did the TG, I fenced a bunch of loot too,but did not run into the bug. Since then, when I do the TG, I be a good little thief and only fence what and when I need to in order to keep the bug at bay. :shrug:

Yeah, unfortunately I did have to console my way in using

setstage TG10Boots 10

to acquire the quest that way - but now everything is running smoothly