for question #1:
A person who is at the Starting Member level will never have a star. It's not until they have reached the Member Level 1 that they will receive a star.
Here are the defaults:
0 - Starting Member Level (this level will never receive a star)
50 - Member Level 1 (this level gets 1 star)
100 - Member Level 2 (this level gets 2 stars)
500 - Member Level 3 (this level gets 3 stars)
1000 - Member Level 4 (this level gets 4 stars)
2000 - Member Level 5 (this level gets 5 stars)
For question #2, goto the Members page, in the right column will be icons where you can lock or delete a member.