You have my full support for the 5D2. Good choice, and a most excellent companion to a 7D.
As for settings, it depends what I'm shooting, but normally the main points would be...
- I only ever shoot raw, and normally process in Lightroom, so many settings are irrelevant for me.
- Unless you have a very good reason to be using HTP then leave it disabled.
- If shooting to JPEG I would disable ALO. If shooting raw it does not matter about this setting.
- I shoot with Neutral picture style so my in camera histogram is not artificially effed up by in camera preview processing.
- I have focusing transferred to the AF-On button only.
- I enable highlight warnings and the RGB histogram.
- I have pictures rotate on the PC but not on the camera.
- I nearly always shoot manual, with spot metering, and I check my histogram and look for blinkies.
- I'm not afraid to use the outer focus points, but if they aren't up to the task then I'll switch to centre point and manage as necessary. I will enable AF assist points when it makes sense to.
That's off the top of my head. If I think of anything else I'll update.
Happy shooting