As a slight update, I took your advice and I put the fan before the radiator, and everything seems fine! The only thing that's really eating away at me now is the projected tubing path from the CPU to the 120x1 radiator. Here's a
photo depicting the current tube-less setup. Pretty much, I think the tube would just be slightly neater if I used a 90 degree fitting on the CPU output. I don't think there will be any problems with it as it is. The thing that gets me about it though... I
do have an extra 90 degree fitting lying around,
but... it's white. I was originally going to use it as a nifty rotating fill tube that that would exist behind the 5 1/4 bay cover above my reservoir, but I sort of put that idea on hold for the time being. Anyway, if I wanted to wait, I would probably have to order it from Performance-PCs as they're in Florida, so I get stuff in two days using USPS Priority (2nd cheapest shipping option). In other words, I wouldn't be able to finish until Wednesday!
I've also got an e-mail out to Koolance about their QD3 quick disconnects. I still don't know if it's viable to leave one disconnected while the loop is operating. I still like the idea of using it as a tidier drain port.
There's nothing wrong with the Corsair 800D because it was never meant to be made solely for the watercooling crowd.
I might just be looking at things in a more general way. I consider the 800D to be more of an enthusiast case given its size and accessibility. To me, enthusiasts are the type that would probably use custom water cooling, so you would expect a case like that to provide more support.
If you want to make it a watercooling case, you've got no choice but to pop some rivets and bring out the dremel.
I don't actually own a drill or a dremel.

I think I'm going to go buy a dremel tomorrow as I've been manually filing things down, and yeesh... that takes
a lot of effort.

I'd also like to remove some of the remnants of the old tool-less drive bay stuff. I also want to pick up a washer to use with the reservoirs bolts as the heads are kinda small. I could also just buy different bolts.
Not sure if I will be making a watercooled gaming HTPC but if I did, it'll be the Cooler Master N200 + 120mm and 240mm radiators or Cooler Master Elite 120 + Alphacool NexXxoS Monsta 120mm. The results of the
Cooler Master Elite 120 looks stunning.
Wow, that Elite build is pretty sweet! I wouldn't have imagined that all that would even fit in there!

Although, he said he filed down some of the static memory clips, but since the video card stands straight up, wouldn't it just have been less destructive to remove the backplate on the GPU? In some of my reading, it sounded like people bought those because they provide support since full-GPU blocks are really heavy and video cards typically lie flat in cases.
Anyway, I don't really
need to water cool my gaming HTPC. What I really need to do is find out what in it is making this noise I keep hearing. It sounds like a very slight grinding noise sort of like "tsk" or "tick". I could also pick up one of those large GPU cooling replacement things. Newegg actually has that Accelero Extreme III on sale for $50 (normally $100).