You would create two connections in DW with the two MYSQL users and use one of them for admin and one for the rest of your site... It sounds like you understand.
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.