Simple question...

When you become Harbinger, do the containers in Kodlak's former room reset after awhile, like other containers do?

I don't think they do, but I put my stuff in a container in there once, and it immediately became "stolen." I'd not risk it.

According to the entry on http://www.uesp.net/wiki/Skyrim_talk:Jorrvaskr there is one safe container after becoming Harbinger.