I just picked up my 709 last night (replacing a TX-DS696 that got taken out by lightning) and I'm still trying to figure everything out.

Probably important to note that I also replaced my TV (a big ol' 36" Sony Wega) with a nice slim 52" Sharp Aquos. And the old TV was just HDMI ready, not HDMI, so I had to use it in conjunction with an HD receiver, and an HDMI router (since the Wega had only a single HDMI port and I also have a Blu-Ray). So, this new setup means I get rid of two components - yay!
I don't subscribe to any cable or satellite tv - I just use the excellent OTA signals, with a good outdoor antenna, and that works great for me. I guess I thought that ALL of the video would be run through the 709, but when I looked at the back, I realized that there was no HD antenna connection, so my antenna is connected directly to the TV. So, my first question is...how the heck do I get the TV sound to play through my receiver/speakers? I see a weird looking tiny plug, and an optical plug...and yes I have read the manual, and these are the two methods that it lists. I have no optical cord...and I don't have any idea what that other tiny plug is.
Can anyone 1) give me some idea of what that little plug is and what kind of cable I would need? And 2) Is one connection better than the other?
I was going to connect the Bluray up straight to an HDMI port in the TV, until I realized that I had this audio issue, so I connected it to the 709 and then the HDMI MAIN out to the TV...and that seems to do the trick. One thing that I noticed - when we watched the Blu Ray on the tv - it displayed this little "no audio" icon at the bottom of the screen (we had audio through the receiver speakers - it worked great), as if the receiver was smart enough to talk to the tv and tell it that it was directing the audio to the speakers and not the tv.

Does that even MAKE sense? I would have expected to have to mute the tv speakers....I never thought that it would do that for me. Weird?? Anyone know about this? I could find nothing in the manual.
One more thing...the receiver display...does it always stay off until you use it? I can change the tuning station, and then bam...a second later, it turns off. Again, I can't find anything in the manual on this.
Thanks for any help you can provide!