> I din't never like that -ig- in there anyway.

The -ig- doesn't have any point (a bit like some threads), your right. Istigkeit would have to be something like isiness or isity, rather than isness, if it wasn't nonsense in the first place. It's not much of a word really - I'd like to see a Duden entry for it though!
Clearly Meister whats-his-name who coined this one was aiming for something with a ring to it (Istkeit sounds crap), and for something with a pseudo-official look. I take it this was done with some tongue planted in cheek.
Nice variations by the way Faldage, though I can't see Pons rushing to include them in their next volume.

This is the first time I've ventured beyond the threaded equator since getting to the Board. And it's good to see this rubric has finally been opened up!