Kneadatite"Green Stuff" Blue/Yellow Epoxy Putty

If i used it to sculpt an armature for a mini and sculpt over with super sculpy, could i safely bake the green stuff?

Someone has already asked it, but didn't get the proper answer for it so here it is again: how much greenstuff does this include (expressed in gramms)

How are we supposed to open the product? If cut tube, won't that dry it out? My tube has one end sealed, and the other open -- is that normal?

Is it sandable or can you file it ?