You can install extensions on dreamweaver cc by using the command line, or the free third party extension manager from DMXZone: http://www.dmxzone.com/go/22670/dmxzone-extension-manager-for-dreamweaver/
The php.ini file looks correct, and you are using a good php version. So you php installation doesn't seem to be the issue.
Let's get back to the original problem. I see you are having difficulty connecting to your database in Dreamweaver. What is the error exactly? If you post a US phone number and a good time to reach you I can give you a call and try to debug this with you in a screen sharing session to get to the bottom of it.