Hacky,

I am not poisitive about the Pioneer HDTV but the only other device you list that can utilize RS232 is the B&K AVR307 (awesome receiver). Most of the benefit over IR (even if you could get the 232 module) for that device would be two way serial communication; that is not availible on the T2. Everything else you can accomplish through presets.

All other devices you listed have discrete codes for on/off and inputs so using the video and sync modules for that purpose would be redundant.

I have found a useful feature for the video sync sensor: Dish network HD reciever. The video sync sensor can be used for detecting whether the receiver is providing SD or HD. Logic can be written to keep the output toggled to the correct setting. (The RCA STC-100 has discrete HD/SD output codes, so no need here.)

Rob