About phoenix card and thunderbolt expander: theoretical number is 3 chained thunderbolt expander with 3 pci-e slot each (total 9) and you have 6 thunderbolt input so you capped to 20 input that declared in description. As my experience any lfg card that i had do not work on system above 10.6.8, and phoenix card stop working above 10.8 (with any combine of driver include a new ones for 10.10).
I have also decklink quad (with last driver) more than 2 input catalyst crashed.
About receive streaming video, there are on forum, looking for citp software for catalyst (https://itunes.apple.com/gb/app/citp...11784333?mt=12).