Even after watching the videos where he includes his stick output, I still don't think that was done all in one run. It's possible, sure, but with only losing one life to Stone-Like? I doubt it.
Personally, I don't think coop on Touhou is feasible. Ikaruga, Mushihime-sama, and most of the shumps I've seen all have huge bosses, with hitboxes to match. In Touhou, the best we can get are bosses like Mokou and Yuyuko, who both have an expanded hit zone due to their extra items (phoenix wings, the fan thing). Without that extra size, both players would be competing against each other in the higher difficulties just to deal damage, much less get into the tiny holes and continue to deal damage.