Questions
Q1
Will A68N-5000 support Dolby HD and DTS HD MA output through HDMI port?

Yes, both Dolby HD and DTS HD MA will support by motherboard's HDMI port.

Also it could support by add on VGA card's HDMI port if the HDMI is version 1.3 or higher.

However, it will need an external decoder for these two audio formats to work.