For Mac, I don't know if Yosemite moved anything around, but to get system specs in Mavericks you can use 'system report' from the 'about this mac' apple menu item or the 'system information' app (utilities folder); in earlier versions use 'System Profiler'.
Saves can be zipped by right clicking on the folder(s) and selecting Compress, and are the folder:
~/Documents/Larian Studios/Divinity Original Sin/PlayerProfiles/<ProfileName>/Savegames