I've been using the cheaper SBH-20 BT headset in a similar way to your SBH-52 'walkman remote' hack. Having a remote enhances the experience immeasurably. Just wondering are you able to control volume through the SBH-52? Due to the way the SBH-20 operates remote volume control is non-functional.
Also can the SBH-52 display track info when music is being output through your PHA-2's audio jack?
Unfortunately you cannot control de volume also with the SBH-52, on the other hand, if you connect the PHA-2 to the F886 it is still treated as "headphone output", in other words, yes. I can see the tittle of my songs using the PHA-2 no problem, and I love it because the volume is located in the amplifier, so I can change that if needed.