Sorry in advance for the newbie-ish post

I am looking at buying my first BD player and have chosen three players in three price ranges based on info gather from this forum: the Panasonic BD35K (~$230), Panasonic BD55K (~$330), and the Pioneer 51FD (~$420).
Here is my setup:
Kuro 5010 plasma (it is awesome IMO) - speakers not attached
Kef 104/2 speakers (2 speakers only - no 5.1 or 7.1)
Denon DVD2800 DVD player
Comcast HD DVR
Panasonic SA XR57 Receiver
Connections:
Comcast video to Kuro via HDMI (video only due to lack of speakers on Kuro
Comcast audio to XR57 via optical
Denon DVD to Kuro via component cables (no HDMI on Denon)
Denon DVD audio to XR57 via coaxial
The HD video with the Comcast and Kuro is truly awesome. Audio is fine also. DVD's are not as crisp as the HD channels, but very good.
Questions:
(1) I read some posts saying the two Panny BD players (35 and 55) are not as good at playing DVD's (as decidated DVD players). Is this true with all BD players? Would the more expense 51FD play DVD's better? Even if it does, should I get the cheaper BD and continue to use Denon 2800 for DVD's?
(2) If you recommend the less expensive BD35K, should I connect it directly to the Kuro via HDMI, then use a coaxial or optical output for the audio (remember, I am only using a 2 speaker set up)?
(3) If I get a new receiver (possibly the Integra 5.9), would you recommend one of the more expensive BD players to get better audio? If so, should I use HDMI for both audio and video, or HDMI for video and coaxial or optical for audio? I've been doing a little reading about DTS-HD audio but don't really understand it.
Again, sorry in advance for all of the questions.
