Congrats on the pond project - I manage several cool water species fisheries in NE and love your plans.
Matt and Scott are great resources - ring them both and start the discussion. Proceed with confidence.
Follow Bill's advice, he wrote the book, I'm just a Cody apostle.
On crayfish - Per Cody use papershells, not northerns. Northern adults top out at a size invulnerable to the gape of most SMB and WE and can lead to major issues [denuding macophytes, turbidity, excessive burrows, etc.] I believe papershell adult max size allows their populations to be more effectively managed.
In order to help relieve pressure the forage base I would strongly consider NOT adding spawning structure for the SMB. They will still pull off occasional beds on the clay without rock beds, but you don't need major SMB recruitment anyhow as forage base will be a larger concern. However, if you do end up building SMB beds I elevate mine using a pallet so they do not become buried in silt/organic matter after a few years. My bed designs are somewhere here on the forum. They worked very well and addressed all the issues I encountered in my previous several seasons of SMB production.
GSH will hammer larval fish of all species, and while Bill's obviously correct they add another layer of forage, I wonder the significance of their predation impact on larval SFS and BNM. I raised FHM and GSH in a cell this Summer and had almost zero FHM recruitment, but the GSH were all robust...HMMMMM. I am assuming GSH focused on zooplankton [had dense phytoplankton bloom all Summer which also was strange] and larval FHM all Summer long - makes sense. Just something to consider...GSH do impact a fishery in a significant way - there are pros and cons, I still don't know how I feel about GSH role in my fisheries and I've been messing with them for over 10 years. Bill wouldn't recommend them without the direct experience with them, so he must have witnessed SFS/BNM and GSH coexist well.
One last thing to consider: Purchase trained SMB and YP - will help relieve pressure off your forage base significantly. Scott and Matt both can source the trained YP for you [Lake Erie genetics], the SMB you may need to train yourself in cages. It's not difficult, but start with small SMB it's much easier [1-2"].
Lastly - if you will have a dock you can provide supplemental feeding to your WE, SMB and YP using live, then cut bait. I use BG when available, but also buy frozen Tilapia fillets and Catfish bellies. Not all fish train on fillets, but those that do grow fast and are a blast to feed...they become pets.