Julie,
Thanks for all your feedback. I definitely agree with choosing what groups (or actions in general) are pushed to a users timeline. If users can create content that will then get pushed to other users activity stream, you can run into issues without a lot of moderation.
As for where the activity shows up, that's up to Facebook by default. All activity is entered into the users Activity Log, which is part of the Timeline. The default activity action is to "Let Facebook choose to show it". That will then push the event to the user's profile feed, their friends feed, and/or the ticker depending on social relevance of that action to the viewer. If the action, site, or app is popular among a group of friends, it's more likely to appear to those friends when any of them take that action.
Finally, I'm not sure what 'nasty old login issue with mobiles' you're mentioning is. I know we've worked through issues in the past, but refresh me on what's happening right now (what to do, what device has issues, etc). Also, what are you expecting in JomSocial 3.0? 2.8 just came out, and I haven't seen any clue as to a roadmap of what 3.0 will offer.
Thanks,
Alex