Hi Slurp, welcome to the forum! Congrats, and it's very cool you could buy the pond you first learned to fish on!

Grass Carp won't eat Filamentous algae, but can help cut town on other plants. RES only spawn once a year, so don't count on them for much in the way of providing a lot of extra forage, though definitely a great addition to stock.

I'd be really surprised that you'd be BG heavy in an Iowa pond and not LMB heavy, but I guess anything is possible. I don't think you would harm anything by removing a few to several BG per kid. How many LMB did you sample for WR?

YP are excellent table fare and great LMB forage also, but you'll need some pretty heavy, submerged grasses or cover for them to do very well (and not quickly extirpated) with LMB present.

I'd spend a year getting to know as much as I could about all the fish in the pond before doing much more stocking. BTW, did you fish for Catfish before adding any? Too many cats could cause muddying of the water.

Dye is pretty good at blocking sunlight to reduce FA growth, but it also reduces the growth of the base of your food chain, and reduces your pond's overall production potential too.