Thanks for the thoughts. I like the idea of using wire to wrap pallets (etc.) together. We used some light rope and zip ties (too small). I have some T-posts and will probably knock a few in, at least for the tire reefs.
My wife scored some discarded ~3-4" diameter PVC pipes. Still trying to decide what to do. Have heard of the PVC Christmas trees, but I don't want to go buying a bunch of PVC tees at the hardware store. I might cut them to 2 or 3 feet, group some parallel to the bottom of the pond, and "plant" some vertically like bobad said.
