I got lucky with the rock I purchased. There was only 13 (lucky number) pieces, most of which were pretty large and solid. And the rocks are all gnarly, so they locked together like legos. So after setting out the rocks, planning which goes where, and some trial-and-error, I ended up with the current aquascape without any epoxy, drilling, rods/pipes, or ties. In person, it looks more gravity-defying, but it's surprisingly extremely stable.
All pumps are on. The sand got moved around somewhat by the Vortechs, but not a whole lot. It's all pretty much where it's going to be now. I was afraid the pumps kicking up a lot of sand, but it didn't happen.
Ya, I wanted good flow and a lot of room for fish to move about. A small concern I have is there might not be enough sheltered areas for fish to sleep. The left side might look like it's a good area, but it's really very open (I'll take more pics this weekend). There's some space on the right structure, but fish are going to be crammed in there for the night
The rock quality is awesome. I wanted Marshalls, but they don't collect there these days, so this was my second choice. I'm very happy with what I got.
BTW, you plan on starting a tank again? Another 300g would be sweet