I have several comments about this plan.
First, IMHO the idea of placing all the DirecTV equipment in one place and then driving Tvs in different rooms in the house is very "iffy" to say the least. RF control through walls in the house often does not work very well, and the devices that carry remote commands back through the cables are not too reliable either. Additionally you do not seem to realize that if you have a DirecTv box in a central location and want to connect a non-RVU HDTV to it, you will need an HDMI cable running from the box (long, in-wall quality, expensive), through the walls to the remote TV. RG6 will not work for HD.
So let's look at the configuration.
First, the HR44 will need to go somewhere where it can drive a local TV and be connected to the whole home network. This really should be in the family room, because the client boxes and RVU TVs will always be slower than the HR44 and I think the longer response time will drive you crazy.
The RVU TVs and DirecTV genie clients are NOT connected directly to the HR44, they are connected to the Whole Home network which runs on the RG6 carrying the satellite signals, so the cables run back to the AV closet.
If it were me, I would install an HDDVR in the Kid's room. Putting a client in there (either a DirecTV client or an RVU TV) is NOT a good solution because you can't stop the kids watching anything in the HR44 playlist (Clients do not have their own parental controls), or deleting stuff in the playlist.
Your non-RVU Tvs would need to be connected to a DirecTV box using HDMI. You could use a client box, or a small receiver like the H25, your monthly cost will be the same. The H25 can be wall mounted like the Genie client so that would avoid a long HDMI cable run.
Let's assume for the moment you put the HR44 in the family room. If you have four RVU Tvs, you can only use three at a time anyway, so the one in the family room would not use RVU because it would be directly connected to the HR44.
One other thing to mention. With an HR44 and one HD DVR you are using up seven tuner slots. If you have another HDDVR, say in the game room, that will use nine slots so you will get an SWM16 as part of the install. If you do this later it will be expensive.
So if it were me I would have:
HR44 in family room.
HR2x DVR in kids room
HR2x DVR in game room.
RVU TV in loft
Directv client driving second game room TV
Direct client driving outside TV.
That way I have a maximum of three RVU TVs/clients, I get the response time I need in the family room and in the game room, and I can keep the kids on their own system which can have parental controls and does not share the main playlist