Network set up questions

This is my first post. I don't have my TiVo Roamio Plus and 3 Minis yet, but plan to get it this weekend.

I am switching from DISH to Comcast Xfinity; I already have a Comcast connection for my ramp onto the internet.

While I have both ethernet and coax drops, I think I will try to set up a MoCA network.

I will need to add a splitter where the service comes in with one line going to my existing modem. I understand that I should put a point-of-entry filter to stop MoCA traffic from exiting my house. My question is should this filter be before the modem connection or should I use a 2-way splitter with one line going directly to the modem and the other line have the filter before splitting again to all my TiVo devices?

I've heard that all splitters are not created equally, any suggestions of features that I should look for?

Is it correct that I'll need both ethernet and coax connections to the Pro and only coax to the minis?

Thanks in advance for any insights or suggestions.