Tweak runs under standard privileges, so you shouldn't accidentally do something you didn't mean to and find your computer is broken.
Tweak combines lots of system utilities all into one place so you can easily find what you're looking for
Ubuntu Tweak is a "play, don't say" application. The best way you'll learn about it is to try it out for yourself instead of reading an article. It's stored in the standard repositories (ubuntu-tweak) and installs to Applications > System Tools > Ubuntu Tweak.
If you're still skeptical, here's a partial list of what you can do:
- Search popular applications
- Update Ubuntu
- Change the login screen
- Basic configuration of Compiz and title bars
- Manage desktop icons
- Change power settings