Pioneer IP-Bus / AV-Bus install help

I just bought a 2004' Pioneer AVH--P600DVD indash player/tuner/controller and am finishing up the installation, desk testing the unit in the vehicle. I had some previous Pioneer components left over from a never installed system. And am having problems getting them connected, and finding ANY knowledge about Pioneer's AV Bus and IP-Bus connection methods

I already owned a XDV-9 dvd changer (the older 6disc cd/dvd changer).

I have already used the 1 6600dvd Composite RCA Video/Audio VTR input for input into the head unit of PS/2, XBOX, Satellite TV Tuner (remote switched) and was under the impression (from both the dealer and the offical web site that the 6600 has DVD Changer controls) that the XDV-9 would send audio and video to the 6600 via IP bus (It has standard Composite rca A/V for use in a "Stand-alone mmode".  I have the IPBus control cable from the XDV-9 to the head unit andI can hear audio, but no video is transfering. I was told that I would need to have the AV-Bus input on the 6600dvd connected to the dvd changer as well (however the XDV-9 has no avbus out, just IPbus and composite Front/Rear Video and 1 set of l/r RCA). I did some digging around and found that the newer XDV-90 also doesnt have a AV-Bus out, but a Composite to AV-Bus convertor cable, more on that in the rest of the question.

 Like I said, I did some research and see that the XDV-90 changer has a "composite" rca video to AV-Bus conversion cable. Part Number:  CDE7037. But it looks like the Pioneer A/V setup perfers to have a "A/V Bus Master unit" functions they have delegated to the TV Tuner BOX (which does have Audio out over IP-Bus, and Video out via AV-Bus) 

I ordered from a local Pioneer dealer a GEX-6400TV tuner because my local Pioneer rep told me that this tv tuner would take the (audio) IPbus, and video (composite rca video out) from the XDV-9/XDV-90 and convert it in the chain at the tv box which will then be connected to the 6600dvd with needed AVBus AND IPbus.

Thought I had it all figured out by my local pioneer shop ordering the tv box, but I took a look at what install manuals for the GEX-6400TV online and see that IT (GEX-6400TV) DOESNT have a "composite rca video in" only AVbus/IPBUS in/out, which is the same problem I had to begin, the changer feeds video via rca. So output from the XDV-9 has the audio option via Composite RCA or IPBus, but video output is stricly Composite RCA.

1st question, anyone here a expert on Pioneer that could tell me exactly what to do, or had any experience with the AV/IP Bus.

2nd question, the above mentioned part is only listed on the XDV-90 accessories page, but I cant see how Composite out from a XDV-9 is any diffrent that composite out on a XDV-90 probally a part designed from the short comming of their head units expecting "Tuner controlled devices" transfering video on the AV-Bus. Any one know or used the  rca video to AV-Bus conversion cable. Part Number:  CDE7037 and understand it?

3rd question, I guess I didnt need the TV Tuner box, as it has IP/AV Bus in and outs just like my actual 6600dvd, this is for the GEX-6400TV) hide away unit, In a little more research I see that the previous model TV Tuner box had actual Composite Video inputs, I assume that this tv tuner modified the rca in to a AV Bus signal beacuse all install diagrams show the older tv unit connecting to head units strictly IP/AV bus and all external single dvd players/multi dvd changers feeding combinations of Composte Video/Audio & IPbus to the head unit with a MIX. New one doesnt, anyone have any experience with the older unit that might be able to confirm this?

Sorry for the long winded post, pioneerelectronics.com hasn't answered support emails from me in 4 months, and its obvious the local dealer doesnt know anything except how to take my cash.

Septic

No resident experts just dying to give me some info? ;)