I have heard that 2 weeks is the magic number as far as Dry Hopping. However, I have left hops in for as long as a month and had no ill effects (Life got in the way).
As far as the bubbling. I don't tend to trust that for the reason RM-MN mentioned. Gravity readings will let you know for...
I live in Austin, so its not uncommon to run into a fellow Home Brewer..
However, I still get the occasional:
"Is that even legal!?"
"That seems like too much work."
or my favorite.. "Does it taste better than BL?"