There shouldn't be a problem with changing only some of the server behaviors. Just to make sure, I would make a backup copy of the site before making any modifications.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.