A lot of what I've learned about customizing Firefox came from many different people asking me a question like - "Can you do this in Firefox?"
- Can you remove the Set as Background Image menuitem?
- Can you easily change the Firefox branding?
- Can you turn off private browsing?
- Can you block access to local files?
- Can you disable safe mode?
Through the research I did into these types of questions, I learned a lot about how Firefox works and how to modify it to meet the needs of various people and organizations. And a lot of what I learned ended up in the new CCK2.
Have you ever asked the question "Can you do this in Firefox?"