I had some leftover MMF last weekend from a sheet cake I did for a church. I have been playing with it, trying it in molds, etc. Does the MMF really need to be refridgerated or can it be left out on the counter as long as it is double wrapped in saran wrap? Also, does MMF work with Gum Tex in order to make it hard? Or do I have to use regular fondant for hard decorations?

no frig, will keep well sealed.
yes, works w/ gum tex

if you search forums, lots of tips and tricks offered about it. (one even says use Fasteeth!!)

does not have to be refrigerated, can last for months at room temp. not sure about the gumtex question. If you leave it out long enough it will get hard. I've read on here many times that it takes a while to harden.

Thank you Debbie2881 and Doug for the answers. I just didn't want to make anyone sick.

Not at all...
MMF has no dairy product in it, it can't possibly make anybody sick. Unless probably it's 15 yrs. old.
I'ts all water, sugar and Marshmallow.