wifi analytics on orbi app

I just cut the cord with verizon and am using them for internet only. I went twith Youtube TV, Netflix and a Roku stick on all 5 of our TV sets. I have a verizon quantum gateway router and hooked up my Orbi RBR50 to it in a/p mode per the directions on the netgear community site. Currents speed is 75/75 Mbps. Verizon is willing to upgrade me for same price to 200 Mbps. I am told the quantum router can handle the speed and want to be sure the Orbi AC3000 tri band router system can as well. Apparently I have to use an ethernet cable from the verizon ONT box to hook into the verizon router in order to get the upgraded speed. I am told it can't be done through the coax cable. Before I go through all this trouble and expense (Verizon is charging $150 for ethernet hookup) I want to be sure I will still be able to run my wifi through the Orbi mesh tri band system. I am told I may  have to upgrade to the verizon fios g3100 router if my verizon quantum gateway doesn't work and again want to be sure that my orbi is compatible with it. Any help greatly appreciated. My house its 5500 square feet and i am hoping this will help my wifi to be seemless throughout the house.TV