Using component DVD player or receiver with HDMI monitor/TV?

I would add both HDMI and Component. You need to make sure that your Denon can do the video conversion for you for the component sources, otherwise you may need all of the video source types to have a monitor cable. In the future you may decide to replace the receiver and then you can use the HDMI. I also believe in the next guy and future proofing the set up. each of those RCA's are coax and can be re-purposed if enough length is left over. I would also add ethernet as well.