Let me answer a couple of your questions. In this case, the fish grabbed the bottom spinner. I would expect more bites on the bottom because I think a fish is more likely to be looking up at the three spinners rather than down. We have all heard that fish see better looking up better than they do looking down. If I were fishing deep water, like Swan Island, I would fish exactly the same rig at the same depth. Friends of mine have been very successful putting out no more than 20 feet of line.
I like the idea of three rigs because they probably look alot more like a school of bait than a single spinner would. Using sliders instead of three way swivels would allow you to spread the spinners out more and let you close them up if you got a fish on the bottom spread. Sounds like a good idea.
My next experiment will be to run three Coyote spoons directly off the main line. I'll use the smallest size bead chain swivels in order to give the spoon as much action as I can. I'm sure the action will be less than it would be if the spoons were on a leader. On the other hand, the action might just right for attracting a big fat salmon.
Sorry Slayer, I don't have a camera to show you a picture. How about I just hand you one?