Can I unlock skills on maps with skill restrictions? (For example, California 2)

Yes! Some level creators have designed their maps with skill restrictions in mind, but you can override this in your singleplayer or server settings.

For singleplayer:

1. Click the Advanced button
2. Scroll down to Players
3. Enable Prevent Level Skill Overrides

For server hosts:

1. Open the U3DS folder, then the Servers folder
2. Open the folder for your specific server
3. Edit Config.txt in a text editor
4. Search for Prevent_Level_Skill_Overrides and change that line to: Prevent_Level_Skill_Overrides True