Connection(s) to Existing Database

I have an existing client php site with a database I built and connected to with DW db connections and server behaviors, etc., that utilize a dynamic master/detail page relationship. The database is simple, with a table for members and one for users. Consequently, I already have a Connection folder and file. In addition, as part of the above, I already have a simple CMS to handle member/user edits, additions, and deletions of database records. Again, all built DW server behaviors prior to my having any WA products. Also, obviously we are dealing with a live server and not a testing server situation.

1. Now I want to add PowerCMS to the mix. I have already added the PowerCMS tables to the existing database. My first thought is that I want to leave the existing CMS as is, and use PowerCMS to "manage" the rest of the static site pages. Is that the recommended approach, as opposed to abandoning the existing CMS in favor of using PowerCMS to manage the entire site?

2. Assuming that I leave the current CMS in place, now the question is what to do with the Connections folder at the "root" of the CMS100 folder. I would prefer to leave all the PowerCMS folders and files inside of the CMS100 folder at the site root to keep things tidy, instead of placing them separately at the site root (where the other Connection folder resides). With the CMS100 folder in place at the site root, it seems like I would need a second database connection for the benefit of the PowerCMS files. Do I really need more than one connection to the same database with this scenario?

3. I suppose another option is to create a second database for PowerCMS and make the connection to that database, but that seems somewhat redundant and unnecessary. True?

4. How do you recommend I proceed in this situation?

Thanks,
Robert