The best way to verify this is to use a normal CRT television set and set the outputs of your DeckLink card to composite. This will tell if the issue here is really a delay introduced by your LCD or something else.
Yes, you’ll need a valid analog video signal for the card to see the XLR audio. If you don’t have a video source available, loop the output of the card back to its inputs.
The HD Pro 4:4:4 does not support 2K or HDSL. The HDLink is not compatible with the Apple 30″ Cinema Display as it does not have dual link DVI which is used by the display.
Please also let us know your system configuration, including the make/model of your motherboard. Send use the NFO file you get by going to Start -> Run and typing “msinfo32”.