Welcome to the forum! Congrats on the new system, and I'll take a shot at answering your questions:
1 - Some shows have a lot of surround effects, and some have very little (or none). So, don't be shocked if you don't hear a lot going on in the rear speakers. You'll want to make sure that your blu-ray player is set up to output bitstream audio, and that the Verizon Fios box (that's for TV, right?) is set up to output surround sound. If you have any questions about how to do that, just let us know the model numbers.
2 - As lame as this is...the onscreen display (OSD) on that model will only work over the composite video connection (the yellow RCA "MONITOR OUT" jack). Luckily, your TV has an input for that.
3 - The optical audio output on the TV is for sending digital audio to a receiver. However, if you are already getting all of your audio from HDMI, then you don't need to use it.