Marc -- I'll toss out a few thoughts, but let's hope for other input. I'm not expert on your tough questions. :-)
1)direct sun or shady spot, maybe under dock? I've seen them spawning in both locations. You did not mention what else is in the pond. If LMB are present, you'll need protected locations to give the fatheads a chance, so shady would be good.
2)close to deep water? I don't know, and am not sure why it would matter. If LMB are present, the fatheads will ONLY be in shallow water. They will stay under the top board on the pallet and spawn upside down. They like to spawn on the side of stand pipes, especially in the shade of a dock. They will spawn on the sides or even burrow a little under a big rock.
3)block pallets with small cedars to help give them some protection? Absolutely, especially if LMB are present.
4)minimum water depth? We often used floating boards (e.g., 1 in X 6 in X 10 ft), and staked both ends. Ropes to the stakes would allow the boards to go up and down with water level. The boards would be right up against the shoreline, and the fatheads certainly used them. I don't know if this is optimal, but they certainly use them.
Like I said, these answers are based on limited experience. If any of the other pondmeisters out there can help, PLEASE do so.
