Blu-Ray PS3 Audio/Video Questions re: Onkyo SR674 and Samsung LN52A650

[matthew_m_g]

Hi folks. I'm a n00b here, so please be gentle if I screw up or ask something stupid...

...I'm trying to figure out how to get the best audio and video from my PS3 (80GB MGS 4 Bundle) and Television (LNT52A650 Samsung) via my Onkyo SR-674 receiver. I've been told by friends that there are problems running the audio through the HDMI port (since it's only a 1.1 port) and to use the optical in, otherwise I'll encounter nasty popping and sound artifacts during playback of audio. That, and there are problems with the passthrough video quality of the HDMI on the SR674.

My questions to you fine folks are:

a) Are there legitimate problems with the Onkyo SR 674 receiver and audio/video via HDMI?
b) If I use an optical out on the PS3 for audio, what should I set the Blu-Ray audio playback to--Bitstream or PCM?
c) What is the difference between Bitstream and PCM?
d) Can I get Dolby 5.1/DTS 5.1 with Bitstream using optical on the PS3 to the SR674?
e) When I start to play a Blu-Ray movie on the PS3, my Samsung Television shows a message saying 'Mode Not Supported' before displaying the movie in 1080p/24. Is this because the PS3 is trying to display the movie in 1080p/60, or is it because of something else that I have messed with with the PS3 settings?
f) What is the difference between 1080p/60 and 1080p/24, and which one do I want to have the PS3 display movies in?

Thanks in advance to anyone that takes time out to answer these questions.