It comes with a plate... for the big round frames.. look at my albums, i think i have a picture of my mounting setup.
Your pictures are too small to make anything out, do you have larger versions?
The pulley idea seems like a good one, I also thought of adding an extension to the clutch arm so that less force is required to move it.
You're also right about the tensioning wheel; it simply wouldn't stay in place, and I ended up having to drill through the frame and lock it in place with a bolt. Also I don't think the cheap plastic wheel will last long so I'm going to look for a sprocket to replace it with.
The motor mounts will be the hardest thing to figure out. Someone on here posted pictures (perhaps the ones I tried to view now) of a suspension mounted motor; if someone could provide some detailed instructions on how to built that, I would appreciate it.
I didn't expect this to be a simple install, but I didn't think it would be quite to challenging either. I think if these things are ever going to catch on, they'll have to become more manageable to those lacking in mechanical skills - and patience.