2) Apparently this was first implemented on the new 5 (maybe the 7 as well? not sure). There has been discussion regarding the behavior of these new turn signal stalks aplenty elsewhere so you might want to poke around for that. Since I have not used it yet personally, what I've read is too complex for me to re-tell to you accurately.
3) From what I saw, yeah it looks like its supposed to hold a soda can although I don't think I'll be using that cupholder much.
4) The BMW site contains information regarding compatible bluetooth phones.
5) Seems like the toolkit's location is different from what it used to be. But I don't recall exactly where the new one is vs the old one (i.e. on the E46).