I don't know, this might depend on the year.

xDrive and ABS are permanent (unless they fail). I know on the X3, based off the E46, allows you to shut the whole thing down. I suspect now with BMW's DTC mode, you can turn the whole thing off as well.

The best way to get a drift in a big heavy car like an X would be take it down mountain roads. There, you have more speed to work with. I know with the X3, if you try too hard in a parking lot, all you get is understeer because the front wheels are underdriven. But with a proper set of mountain curves about 80 km/h to play with, it's a totally different story.