Your memory issue is likely from incorrectly setting the initial editor/game data paths when you first ran the editor. Try this:
1) Delete Config.xml in the editor folder (which should be something like SteamApps/common/The Divinity Engine).
2) Start up the editor again. For the editor data path, make sure it's set to the Data/Editor folder (so SteamApps/common/Divinity - Original Sin/Data/Editor). For the game data path, make sure it's set just to the Data folder (so SteamApps/common/Divinity - Original Sin/Data).