1 bulb, per headlight, lights up the 2 angel eye rings. the inner angel eyes is always brighter on the e92 headlight. the interior ring bulb is not on, it "looks" like its on because of the brightness caused by the angel eyes bulb and is merely reflecting the light from its lens or chrome body; it is unavoidable due to the design of the e92.
changing the xenon color - that is just personal taste, if u scroll back and look at the new pics he posted, the color matches pretty well. some people prefer the rings to be bluer than the actual xenons, imo anything looks better than the yellow rings.
most of these things are just intuitive (i dont even have an e92), but in fact, all your questions have been answered in other threads regarding the e92 angel eyes issue. i think u should stay cool til ur car is actuall delievered, and once u get ur hands on it, most of your curiousities will be answered by themselves
and ur lucky that for the e92 the angel eyes are so easy to change, you will have a very simple and rewarding first mod.