1.I really love the bi-xenon,i suggest not buying them only in case you dont use to drive at night often and the extra money to get them is a matter.But even so,they are even helping the car look much better(apart fron enlightning your way).Its a plus that if you drive often at roads with continues curves,the AFS system is quite helpful (and fun).So,YES for the bi xenon
2.Bluetooth kit,another YES !Because of the big display(cant get that without this kit).Because of the security it gives when driving,answering phone without hands and eyes leaving steering wheel and the road.You dont get points if using this(at least at my country its the only legal way to talk in car).
3.Wheels?its definitely depending by your driving attitude.For example i got 17'' cause i do every day many KM to get to work and back(about 170 km's,thats the reason i bought the tdi afterall).If i had it to drive just in my spare time i would definitely had get the 18''.
4.I suggest the usb port.Its much more usable with usb sticks and stuff.AUX is pretty useless.Only (common) disadvantage is there is no track names displayed on screen (only track numbers)
5.WHAT ELSE I RECOMEND YOU : A)electric sunroof(all friends having not a roof get really dissapopinted when they see mine and they all wish they had one on their cars) B)changing speakers.i am about to do that,maybe getting sub and amplifier too,it seem so poor when you turn on the volume(try listening slayer on 2/3 of the volume level and you will understand...) C)roof spoiler