Frist of all congrast!
I don't have any experience with US cars but I'll try some of your questions.
1 no idea
2 Don't see why this option shouldn't be available on the 750
3 Fitting these tires should be no problem, wheels have the same size.
4 You can request paint examples from your dealer.
here are some pictures:
Citrin:
http://www.7post.com/forums/showthre...ght=individual
Azurite:
http://www.autoblog.nl/image-gallery...iews/BMW/760Li
5 You have to do a special request order if you want these things. But there is also down sides, longer leadtime and it is costly. Contact Marc Carson he has that Individual gold M6 on M5board.com he can help you with the right contacts to do such a order in the US.
6 There is a factory option tan available in europe, don't know about the US. Isn't a very dark tan though.
7 I have seen people who painted them in the same colour as the car.
8 no experience on that jet.