definitely do the steering controls. it's worth the trouble. if you want to do the metra axxess, i suggest asking Big (he's an installer/sponsor) about which firmware to use. people where having issues on that. i use PAC-PS and it was easy to tap into the wires. problem is, i forget which wires because it's been 5yrs since i installed that.
as for the USB, i routed the cord through the center console and made a hole inside the arm rest area. you can buy usb finishers on amazon where you have a clean usb socket inside the arm rest. i didnt really care for that so just made a hole (forstner bit), fed the female usb cord, and used hard felt to close up the hole around the cord. no issue with rattling or anything like that.