Is it safe to do this? For example, if in my mod I decide I want to know if the player is using NOM (and is hungry), can I just create a global by the same name of whatever the hunger global in NOM is and reference it in my mod, or will this interfere with how it behaves in the original?

As long as you don't modify the global in your scripts and make sure its characteristics like short or float be same too, I'd say no problem.

Great, thanks.