so, if i use my thunderbolt cable to hook up my late 09 imac. will it be able to use the usb ports on my imac? Also. i got an fw 400 audio interface on my imac. (800 to 400 cable) could music i play on my mbp be redirected through the 800 port of the imac to my audio interface? as it would be a hassle changing out the 800 cable everytime from mbp to imac... any other solutions for this? thanks!