1. Date joined.
2. Date last visited.
I think that is pretty easy and could be done by template edit. Could do it myself if someone gave me the code to insert.
3. Highlight date joined if 3 months or less ago.
3. An alert tag on members not visited for 2 months or more.
4. Different tag colour if member visited within 2 months but not posted.
5. Would also like the admin search results page displaying accounts waiting approval, to show section below it for accounts awaiting email confirmation.