USB is easy with a $12 adapter you can buy off eBay
Axxess AX-TOYUSB (axtoyusb). AUX connector appears to require some additional modification but some have done it here on these forums. I didn't think it was worth it. I have not seen anyone been successful in reusing the OEM mic. Not sure if it is worth it either since it is so easy to snake an aftermarket mic to the same location as where the OEM mic is located. I would not recommend installing a mic on the steering column as it is too noisy there (from experience compared to installation up top).