I don't have VW 12 installed, but it should tell you in online help. If not start the export process for .dwg and look at the version in the pull down menu. The latest one will be the latest version you can import.
Sorry, Vectorworks 11.5 is not compatible with a new MacBook, so even if you got the dongle working VW would more that likely not work. It's also likely you may not find software for a dongle that old that works on the newer Mac OS.
Vectorworks 2011 needs a lot more horsepower than VW 2009 did. I'm not a Mac guy so I'm not sure just how capable your computer is.
As for crashing have you tried running disk utilities and repair permissions?
For slow screen redraws it sounds like a graphics card problem. Check to see if you have the latest drivers.
To troubleshoot this we would need to know your operating system and computer specs.
Please create a signature with that info and your version of VW including updates. Click on the My Stuff link at the top, Edit Profile.
Please create a signature with your version of Vectorworks including update and computer specs including OS. Click on the my stuff link at the top, edit profile.
Then you could have removed the workspaces from the application folder. Vectorworks looks to the user folder for workspaces first, then to the application folder.