Each of those problems has been reported separately a couple times before, so are not necessarily related.
Are you shutting down all non-essential programs (especially anti-virus) before starting the game?
Try starting the game directly from the '..\SteamApps\common\Divinity - Original Sin\Shipping\EoCApp.exe' program file, by right clicking and running as administrator. Does that give the same error?
Please email supportdos@larian.com, with a description of the problem and the report.zip file generated by the
D:OS support tool.