Sorry its taken so long to get back here, I've been far too busy and still will be for a little while, but will definately be getting back to developing this mod again in the very near future!
I'll look into all the problems you've found and will hopefully be able to get an updated version out soon.
What is the difference between following someone and not following someone? When I tested it, it seems like you see everyone, whether or not you are following them.
Also, how does the group function actually work. I see how to create and join groups, but what happens then?
andrew55 - there are two timelines (or should be!), the 'Public timeline' and 'Your timeline'. The public timeline shows everything, regardless of who or where it came from. The 'your' timeline only shows things you post yourself, or things you choose to see (e.g., if you join a group, it then shows in your timeline, or if somebody replies to you it appears in your timeline). It's mainly of use on high traffic sites where lots of users using the same timeline (i.e. Public) means messages you were looking at on page 1 have jumped to page 30 if you refresh a few seconds later, so having a seriously slimmed down personal version really helps.
Groups are basically a way to coordinate how the above works. E.g., instead of me having to tag every user I want to send something to (e.g. @me @you @someone @them check out this post: blah), i can just do "!group check out this post: blah" and it appears in the personal timeline of anyone in the group
when I've got a few minutes spare I'll put some info together on the current position of the mod, so hopefully will have some news for you soon