Comcast internet/phone, Uverse TV- MoCa compatible?

I recently switched to Comcast for internet and phone after years with ATT. I am very happy with the speeds available, but the WiFi range of the supplied gateway/modem (Technicolor DPC3941B) is mediocre at best outside the 1st floor room with the modem. The opposite end of the 1st floor has a spotty signal, and even with a plugin Netgear extender my 2nd story rooms and basement have poor connections. Retrofitting an ethernet network is not practical in my older home, but there are several coax TV outlets upstairs. It has been recommended I use MoCa, but my familiarity with it is not that great. Any help is appreciated-

1) Is it more straightforward to use an outboard adapter with my leased quipment (my Comcast coax is split to feed the Technicolor unit and Arris TMB22 for phone). A friend suggested I buy my own equipment, but am I inviting setup hassles?

2) We still have ATT Uverse TV with multiroom DVR that uses the coax lines ialready here. I assume Uverse has its own MoCa network for that multiroom DVR. If I use the same lines for my Comcast MoCa network, will there be problems? Should I switch my TV to Comcast as well? (Historically I had horrendously bad Comcast TV service, and the people I have called at Concast about a TV switchover have not impressed me with their knowledge and service.)

3) Any eqiuipment recommendations with either setup- outboard keeping Comcast equipment or buying my own modem etc? I assume I'll be splitting the signals along the way and am concerned about signal loss. I don't mind spending more for better equipment, as I hate chasing ghosts that cause signal issues.

Thanks for any and all help!