Good, decent, noble things Liz has done:
1. Save Will when he was a child and hide the medallion to keep him out of pirate trouble.
2. Bargained with Barbosa to leave Port Royal, not to just let her go which would have been the more selfish thing.
3. Takes it upon herself to participate in fighting, etc, and as soon as Jack asks where Will is, she goes to find him.
4. Is the only one to go back for Will
5. Sacrifices herself in marriage to save Will
6. Stands with Will between Norrington and Jack
7. Takes the letters of mark to help Jack and Will
8. Takes the terrible risk of becoming a fugitive just to find Will
9. Takes Norrington under her wing to give him a purpose
10. Persuades Jack to do the right thing.
11. Chains Jack to save the others
12. Is among those who volunteer to risk their lives to find Jack
13. PS: argued for Jack to be released after he saved her.
Pretty bad things she does
1. Doesn't tell anyone right off the bat the compass "doesn't work" for her. This could have gotten them in a lot of trouble.
2. Toys with Norrington
3. Is sometimes patronizing with her father.
4. Doesn't keep the chest safe which screws everyone
5. Chains Jack to the mast because she is afraid of her own feelings
6. Cheats on Will