My humididty, I don't have a way to test it to be honest.
It is very high, the tank is constantly having condensation on the walls so that isn't an issue.
I think that back wall being covered keeps it fairly wet in there.
As for the crypts. I spread them out to about 3-4" apart between each plant, and the dwarf hairgrass I also planted on a roughly 1x1 grid, I pulled it apart today into smaller clumps to do so as I've heard it grows better this way.
Thanks for the reply!