I think there as been a misunderstanding. If not, then I apologize. But, I do not intend to simply release the design, as an "open source" file. I intend to finance the construction of a batch of ASICs chip based on a design, and sell them at cost-to-produce. So that miners can use them.
This can very well be interpreted as "not just open source, but
also affordable physical chips, as doing that on your own isn't affordable", and if this is the intention here, that's perfectly fine.
He's basically taking all the financial risk, and only asks for some help on the design/software side. The only scam I could imagine is that he builds the chips with our help and then decides to use them all for his own mining instead of selling them at affordable prices as promised.
To get back to the technical aspects:
Why do you only get 8MHz out of that circuit? How is it constructed? All the SHA256 rounds in one huge tree of combinational logic? Or is it pipelined?
Do I understand correctly that each SHA256 unit on it gets a throughput of one hash per clock? How deep is the pipeline, i.e. how many clocks is the delay between input data arrival and result availability?