I'm sorry to hear about your problems with the game. Did you buy it on Steam or the Mac App Store? If you bought it on Steam, I'd recommend trying boot camp and playing it in Windows.
While more games are becoming available for Macs now, OS X seems to be far behind the curve for gaming/3D rendering compared to Windows where Nvidia can release driver updates as frequently as they like, rather than relying on OS updates from Apple.
I purchased a retail boxed version of Civ V for Windows back when it first released and now that Steam allows you to download the Mac version as well I just downloaded it off Steam for my rMBP. Never had any issues with crashing on the Windows version unless I was running mods that broke the game. I'll have to play with the graphics settings to see which ones are the culprits to causing the lockup and crash when loading a game because 2880x1800 and 1920x1200 neither one are working and 1440x900 just looks bad.