Our DataBridge v2 extension adds all of the server behaviors back to Dreamweaver, so you can comfortably upgrade without worry.
You would need to update to DataBridge v2 to update any sites to php7.
Most likely the issue you are having with connecting to your database is a problem with your testing server settings in Dreamweaver. Check to make sure the server URL is correct and isn't being rewritten (https and www. should be there if the site redirects to those versions)