the power injector for this particular switch must be where it is initially installed i believe, I could be wrong, but i have a pretty strong feeling they go straight to the switch, and do not power the lnb. (as the lnb is powered by the switch) so moving it would not be an option without rerunning some lines to direct feed it. Also last i heard those power insterters did not like being plugged into powerstrips or ups's it is recommended to feed them directly to ac.
as for moving the wires around, i recommend AGAINST that as the genie is 5 tuners and all other dvrs are two, each of the 8 ways can only provide 8 "feeds" or channels as they are called, the genie uses 5 and each dvr uses 2, so i would guess the genie and 1 dvr and the h25 are on one, and the 3 other dvrs are on the other. It is very important these stay hooked up how they are, if you send more than "8 feeds" to 1 splitter (genie +dvr +dvr = 9) that would cause you missing channels and more problems. these setups are best installed by professionals or people who have a deep and clear understanding of the swm and directv system. Im sure we could walk you through what you need done if it really comes down to that, but it would be alot of trial and error and waiting for replies. if something went wrong. So i recommend against that.
MRV (internet)....
your correct with what your saying in theory, but the ethernet that is no longer approved (you are correct) also no longer works, directv shut it down. You can run a cat line into the hr34 and it will feed internet into the deca cloud, but you still need the receiver decas to get internet onto the receivers them selves. There is no way around this right now that I know of, again, someone correct me if Im wrong. Using the CCK (wired) is currently the preferred and most applicable type of internet install. kinda struggling for words there, but im trying to say what he did works the best in my experience anyway.
MRV(remote playlists)
your bsf idea kinda works, but per directv the only receivers that need bsfs are standard deff equipment. But you have the right idea, a bsf will block out the multiroom viewing, I have a genie and client in my apartment, and my downstairs neighbor has a h25, [ two seperate accounts, we are not stacking just to get that out there

] we both share the same dish as I wired the whole apartment for him when i moved in, and he liked having only 1 dish, I use a BSF to block his box from seeing my genie, so he doesnt have access to my recordings. If you do not want shared playlists at all (each dvr only views what it has recorded) you can put a bsf on everything but the genie and client and that will work. if you know which boxes go to which lines and you have access to rg6 jumpers and directv branded swim splitters you can do some minor rewiring in the onQ box to use bsfs to 'create' seperate clouds (all adult receivers on one splitter, all kids on the other) and put bsf(s) before the splitters (BUT REMEMBER THE "channels" or "FEEDS" stuff that i said before, you need to be posotive of what boxes go to what lines on the splitters.
(additional deca internet information)
im not posotive if the following information applies to the swm16 as well or only the swm32, so hutch im hoping you can correct me here, the two swm outputs from the switch outside (that lead to the two individual splitters) do not share the internet "injection" so the tech should have used a 2way backwards on your cck line to split the cck into 2 outputs and hooked one up to each leg of the swm. I know the swm34 needs this done with a 4way but im not posotive if the swm16 needs it too. So you may need to leave it set up as the tech installed it.
(possibly ignore the above paragraph, need another tech to confirm)
Bottom Line,
yea you can accomplish what you want to do, but is it really worth it? well thats also up to you, but theres alot more involved than just moving the power injector like you thought, so my recommendation as a retired D* Tech and current Comcast tech would be to leave it be.
(outside opinion)
when you said you might send back either the h25 or the client, personally i would send back the client as it robs a tuner from your genie when its live, leaving you with 4, but due to the great many recording tuners you have available, that may not be an issue in your case. The only thing you would really lose out on functionality wise by taking a h25 over a c31 is the ability to pause live tv, which you can do simply by hitting record and then pause instead, so long as the h25 is connected to at least one of the other dvrs in your mrv cloud. Both should be running you the same 6.00 monthly fee at this point.