How do I remove items so they don't show in a profile "latest activity"
Using Jamroom
That explains it then. Move them to your Groups profile using the Change Owner tool, then you can put yourself back into the Members quota.
I hear what you're saying about quotas/profiles/users etc. and appreciate it can be a difficult concept to get ones head around, but they are the 'backbone' of Jamroom and what gives it its infinite versatility to build any type of website. Yes, it does mean that JR is targeted at the more 'tech-savvy' user, just like you, so please stay with it. Things will fall into place as they have with many 100s of other users