I AM READY NOW
I can assist in creating a design for your workflow without pay. if you are ok with it, then we move to integrate.
I have handled similar projects for church-wide live Broadcasts, Okpekpe IAAF RoadRace, Copa Lagos Beach Soccer tournaments to mention a few.
you're correct to suggest NDI, as you intend to route Skype calls into your workflow. Besides expensive Skype Broadcast hardware, Skype NDI is a cost effective solution. OBS may not be so robust though looking at other requirements. let's talk more please.
Projects like this comes off easy for me so I will execute it effortlessly and excellently at the most minimal cost.