None of those have anything to do with STABILITY.
Aft cg is desirable for minimizing the trim load and hence trim drag. Nothing to do with increased, or decreased, stability.
The tail is often an inverted airfoil to more efficiently generate the TRIM download. Nothing to do with stability.
When the trim download is removed the aircraft will, of course, pitch nose down. Simple result of the remaining pitching moment on the aircraft.
I don't have to "look it up" by the way, but thanks for the thoughts.