@titaniumfrycook - lol, perfect, you came out of lurkdom just like me because of this stand! With regards to the bowing upwards of the ridgepole, look a few posts higher at post #236. I'm re-assured to see that indeed it bends upwards like a bow as I thought it would, but at the bottom of that post I also included something I think may be a solution for this bowing of the weaker, more flexible ridgepoles (I happen to have a weaker one too ).
My stand is coming along nicely, but I'm waiting on some more amsteel to do the soft shackles and fixed loop that I proposed in my solution (there's a picture too ). Let me know if you have tested it out and if it works!
I have tied the same knots as you for suspension (double fishermans knot for the loops around the poles, prusiks (but with an extra turnaround) for the toggle thing for my hammock suspension. Not sure about everyone else. I didn't know all that much about tying knots either before I quite recently started hammocking, don't worry, you'll learn quick enough.
With regards to a flatter lay, it's the slack that'll help you there, not the trying to pull it like plank (I think you need a bridge hammock to do it that way, but with a gathered end, the flat lay is acquired differently). Try hanging from 90 to 91 inches and lay on a diagonal instead of like a banana. Also, because you made a DIY hammock, you can try to retie your hammock to become assymetrical. Being one side a bit longer than the other, this should help too.
The thing about the tripods is right IMO. And in this case, I need the amsteel I'm waiting for again. Gonna make me a flux capacitor thing to keep the legs together.