A few quick questions.....

Ok...thinking of going to Drupal from PHPNuke 6.5 (NukeCops release), as I have had a recent problem with updating Content, and no one seems to be able to help me. (Was able to update my content pages fine a few weeks ago, now, everytime I try to update, nothing gets updated :( )

I also heard that Drupal is more stable and secure.

Q#1 and #2 - Can I just upgrade? Or do I have to kill all PHPNuke tables and installations?
Q#3 - Is there a subGreen theme? Like the one on my site?

http://www.tiwahe.com