[Yuan Soong] "I can use John's handy script to fix the "bad" 30-ps."
Yes. It will only affect clips that are 30.00fps.
[Yuan Soong] "What is the best way to convert the 24p (items in b.) to 30p?"
I would simply have Vegas do it at render time. Vegas is very good with managing multiple frame rates in the same project. If you really want to convert the footage before you edit it, you can just render it out to 30p and then edit that footage.
~jr
http://www.johnrofrano.com
http://www.vasst.com