The house is on a concrete slab, so there is no crawlspace. The coax will have to be ran in the attic. But I've made this very easy for them. When I built the house a few years ago, I installed an electrical conduit from the attic down through the wall cavity and through the brick to the outside, just for this purpose. So all he has to do is push/pull the coax up the conduit into the attic. From there all he has to do is stretch the coax across the attic space to another empty conduit that drops straight down into my structured wiring cabinet, which contains 2 homerun coaxes for each location in the home. It's also a walk in attic (via a full sized entry door from the upstairs bonus room) with plenty of room, so he can walk everywhere he needs to go.
All he has to do is mount the dish and pull the cable from it to the wiring closet and he is done. Having said that, the coax from the wiring closet to each location is RG6 but it's copper clad steel (CCS) coax, rated at 3 ghz. I've been told, and read here, that it will work fine so long as the power inverter isn't on it, which it won't be since the inverter will be installed on the new coax the installer runs to the wiring closet (there are electrical receptacles inside the wiring cabinet). But if he'd rather pull new copper core coax to all 5 locations, then that's fine with me just as long as he fishes it through the walls from the attic and into the receptacle boxes like it is now. He can use on of the existing coaxes to pull it right into the box. The boxes at each TV location contain 2 coaxes and 2 Cat5 cables. They are terminated onto Leviton Quickport F connectors (barrel) and RJ25 connectors. The barrel connectors are rated for 3 ghz, so it should work fine.
About the dmarc box. My intention is/was to use it to cover the conduit from the attic and to provide an entry point for the coax/conduit coming from the dish. At any rate, the installer is coming tomorrow, so we'll see how it goes.