The main Personality screen allows you to edit the personality traits of any Sim and many of the system characters. Change abilities, careers, and job performance.
Convert unwanted Sims to a ghost that you can bring up at any time. You can also bring dead sims back to life from previous automatic backups created by the program.
Here you can exchange family members for any other sim or system character. Make the Officer or Pizzaguy a full time part of your family.
Convert any character to/from a child to affect how others treat the character.
Disable the nudity blurring or turn your Sim Neighborhoods into Nudist Colonies.
If that is too much you can change selected system characters to be nude or skeletons or just furry.
Adjust the relationship values for any character. Force them to be In Love or just infatuated with each other. You can even make two characters that have never met love each other.
You are not limited to 5 Livin Large or 8 Hot Date neighborhoods anymore. You can save any neighborhood and restore it at any time. Use this to reverse any unfortunate events and to keep a backup copy of your favorite neighborhoods.
You can save neighborhoods here, bulldoze them and create a new one then restore the original anytime easily.