site sculptor and file types

I normally build my sites with an extension of htm. I do use some php tags in the coding such as the php include tag for my header and footers along with some right column ad areas. I discovered along time ago that I can edit the .htaccess file on my hosting accounts and tell the server to process .htm like php so the apache server works the include statements just fine.
Can this work too with site sculptor? The reason I ask is that some of my sites I want to re-do using this tool and the cms it provides and am afraid there is a lot of pages bookmarked as htm and new pages with the extension of php may be confusing.
I also am curious if all the pages in site sculptor are always saved as php

thanks