I have the E550, but assuming yours is the same minus 3D;
1. Menu--> System --> Anynet+ is here
2. I googled around and found a bunch of different peoples' settings which all looked good on my set. They depend though on your tastes in brightness, color settings (some were a bit muted), etc.
3. Will your receiver do ARC (Audio Return Channel)? Plug the receiver into HDMI 2 on the TV and set the receiver to the right settings (usually "HDMI Control" in its settings). Turn the speakers off on the Samsung and no need for an optical cable. Sound will pass through to the receiver. I'm not sure if it's the Smart technology or what, but my Onkyo 708 receiver turns on automatically with the TV this way.