1) I think there's an OEM M Sport suspension for all xdrive models, you can ask your dealer about it. Its probably gonna be expensive.
2) For the F10 I don't think there's an M Performance upgrade for the suspension. Such is available for the F30 though. For F10 there's M Sport suspension:
http://f10.5post.com/forums/showthread.php?t=474219
3) Yes it can, but a lot of parts are needed. Here's a list:
http://realoem.com/bmw/showparts.do?...80&hg=51&fg=95
You can ask your dealer about it.
4) I guess it depends on the model
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On order - 2017 F15 X5 40d M-sport Individual
Current - 2016 Porsche 991 911 Turbo S w/ Aero Kit
Retired - 2015 F15 X5 50i, Mocha Nappa, M Sport Wheel, Night Vision w/ human recognition, Harman Kardon
Retired - 2011 F10 550i xDrive