Nice drawing Capricorn1 ... could you not leave out the ethernet connection to the Tivo however since you have the NIM acting as the MoCA bridge? Or do the older TiVO's not do MoCA? My setup looks very similar except I don't have the ethernet to the TiVO since my Roamio does MoCA directly and my bridge is an ECB3500T.
You're drawing also demonstrates a good point -- that you can use a Verizon STB if you have a MoCA bridge. Folks should note however that if this were a DVR, you would not be able to use Verizon's portal or app to remotely program it unless you determined the proper port forwards.