On the 8000 NEX if you have an iphone paired with bluetooth (so the smartphone settings are setup as iphone/ipod over bluetooth) can you not plug in an iphone/ipod to USB and have it recognized? In general I'd like my iphone to be paired with bluetooth, but it would be nice to be able to have a passenger plug an iphone in if there was something on there we wanted to listen to. Seems more convenient for a temporary connection than pairing the passenger's phone with bluetooth.

I can plug another iphone in when mine is setup with Bluetooth, and the phone charges, but it doesn't light up the USB1 or USB2 input option on the 8000. 

If your phone is not plugged into usb1, and only connected thru bluetooth, you should be able to plug another iphone into usb1 and setup smartphone setting to usb. Usb2 will not work with iphone, it is for android, solid state drive or usb flash drive. If i am wrong, i will stand corrected.

If the Head unit is in USB mode you can listen to bluetooth audio as long as you don't plug your phone in. It's dumb, but if you want to charge your phone while on bluetooth and still have the USB open for other devices get an external charger. That's right. Don't use the second USB on the unit. It'll have the same issue. Use an external Cigarette charger. Problem solved. 

If your phone is not plugged into usb1, and only connected thru bluetooth, you should be able to plug another iphone into usb1 and setup smartphone setting to usb. Usb2 will not work with iphone, it is for android, solid state drive or usb flash drive. If i am wrong, i will stand corrected.

The installation manual shows:

iPhone with Lightning connector, interface and USB cables only — USB 1 or 2

iPhone with Lightning connector, any intervening adapter — USB 1 only

iPhone with 30-pin connector, D/A to USB/AUX splitter cables — USB 1 or 2

iPhone with 30-pin connector, D/A to USB/RGB splitter cables — USB 1 only

Android — USB 2 only

MirrorLink device — USB 2 only