I'm going to re-read this a couple of times but this post piques my interest a little bit in regards to not feeding these fish.
I guess it would be worth discussing, and maybe experimenting with the possible of effects of limited feedings in this situation. i.e. Enough artificial feed to get aggressive feeders like HSB the nutrients to grow, but keeping the amounts low enough to keep LMB out of the loop. You might be able to get the best of both worlds by providing, say, 40% feedings.
I'd try it without feeding first, as currently planned, and make careful assessments of Wr conditions for both LMB and HSB and if the values were low after 1 year and the threadfins aren't providing enough nutrition for good growth then you could estimate how much food (maximum) is consumed by pond community, then feeding by a factor of .4 or .5 before reassessing after 3 more months.
I believe the presence of fatheads will ultimately be a non-issue but I can't speculate on how successful the threadfins will be at moving biomass up to predators.
In summation, it sounds like a place I'd like to fish someday.
