Dimensions: 10'x10' Pyramid Pole Height: 72" Dimensions of Each of the 8 Pieces: Height: 96.69", Width: 60", Diagonal: 108.74" (this was calculated using a 2" perimeter air gap and assuming the silnylon will stretch 2")
Pole height is 72 inches, subtract 2 inches for air gap and 2 more inches for silnylon stretch  height is 68 inches Distance from center is 60 inches Height of each of the side pieces is sqrt(68*68+60*60) = 90.69 inches (not 96.69  only one digit off  maybe I made a mistake  I thought I made a mistake once but I was wrong) When I have got silnylon that was "60 inches" it was actually a few inches wider, so when you get your fabric you can check this out and maybe make it a bit wider. Width of each piece = 60 inches Diagonal = sqrt(90.69*90.69+60*60) = 108.74
 My plan is to have 8 stake loops for the tent (using the stake loop design from the article). Four for the corners, and one for the middle of each side (one of which is the door).
Good  you might find after using it that middle stakes aren't necesary. For the door, since you have an even number of people, you might want to put a tent stake loop one foot from the door in each direction so it opens in the middle, like it says in the article.
 I will use a #8 coil zipper that will be about 81.5" in length from the bottom for the door.
Good  #5 is all you need though and a tiny bit lighter than #8. Actually, the next time I might try a #3. When you get the zipper, put the pull on it and try it back and forth a bunch simulating what would happen in real life. I bought a #5 zipper and a pull, it seemed like it was the right size, but when I played with it a while it didn't fit right. Better to discover this before you sew it onto the tent.
 I will use a piece of 200D Oxford for reinforcing the apex that will hold the pole.
Good  Will the handle of the trekking pole be pushing against the top of the tent, or will the tip of the treking pole? If it's the tip, is it sharp? That might eventually poke through. Take a piece of the 200D and try to poke through it with the tip using some muscle, simulating a wind storm, and verify it doesn't poke through.
 For stability I want to use five larger stakes for the corners and the door (maybe MSR Ground Hogs???) and then lightweight titanium stakes for the remaining sides.
I use the thin Ti stakes. When I have done this in sandy soil they have pulled out so I put a big rock on each stake, which is not optimum but it got me through the night. If you're in sandy soil, yeah, probably the Ground Hogs are better. Your tent is a little bigger than mine so maybe it needs bigger stakes. There have been threads recently about better stakes for soft ground.
 I plan on strapping two trekking poles together for the center pole.
There has been a thread or two about how to do that.
 In most cases, I envision pitching the pyramid so that there is a 2" air gap.
That works for me. Minimizes condensation. There is only a small amount of air flow inside.
 I will attach NoSeeum perimeter netting that is 12" wide.
Sounds good. I've never worried about insect netting, but here in Oregon and Washington it's possible to avoid periods of heavy insect infestation
I am not quite sure what I am going to do about a floor and whether or not I am going to attach the floor to the pyramid. I have plenty of silnylon to make a floor...I'm just concerned that it will be way too slippery .
Silnylon is pretty slippery. I use a bivy. I think you're resolving this in another thread.
