How do I access the script public methods inside a GLOBAL custom block.

Two of them don't work and I'm assuming the rest don't. The properties work find. just not the methods, how do I define them?

Via a Script instance, passed as a parameter, for example.

Do you really need a global block?
I think Justin and Hoamaru had a workaround to create static functions in DM. Perhaps it would work for you.

The problem here is that I don't know the context and explaining you why and how to do it is too involved. You'd have to learn the basics of classes, etc.