Its an open or close specie?

I don't know what that means.

they want to know if its free to make them or not. Can anyone make them or only be received through the "makers" or designers of the species

Going by the terms on their gumroad listing for the model, it seems about as open as it gets. The only restrictions seem to be 1) don't claim you made the species. 2) don't give away or resell the model/assets, even if modified. (or upload to neos without av protection enabled)

That's pretty much it. beyond that it looks like you can modify/retexture to your hearts content so long as you buy the model and it's for your use.

fluffo doggo

Everytime I see one of these fuckers in vrc I just have to grab their snoots and jiggle em around viciously

As intended!