Not familiar with SONOS...

Kane wrote http://www.tp-link.com/en/article/?id=250 Nice link !!!

http://www.tp-link.com/en/article/?id=227

You can set your network like: 1, bridge )))) (((( bridge mode, 2, or AP )))) (((( client mode, 3, or AP )))) (((( Repeater. Make sure the lan IP of both of your 7510 are different but in the same...

Not familiar with WDTV, turn to WDTV for advices.

Not in the compatibility list, may not compatible. http://www.tp-link.com/en/support/3g-comp-list/?model=TL-MR3040&location=1151