MECQEMA

Brandon never said that harmony tried to use malatium... He says that sazed tried it during the first trilogy, and the only time sazed had access to it was(probably) during the first book, and he " couldn't get very far" because malatium probably stores one of those weird spiritual attributes that would have taken much more time to figure than he had.

O Peter kind of sort of answered 1 in the reddit post

I don't know if spook made it, but it seems possible. Peter described the table like this: Notice the focus on Roshar which probably means the table was made at the time of SA, which happens just before era 2. And if spook really did have a 100 year rule where he was specifically studying hemalurgy, I think he could have the info to do it, except for the God metals but maybe marsh knew and told him? Who knows. I think it's more likely the chart was made by some arcanist or probably khriss. (or maybe storming jasnah made idk)

F-pewter does make your muscles bigger. (see: sazed any time he uses it)