Mr Optimistic, quote:
"Is there any evidence or reason to suspect that the a/c is difficult to hand fly ?"
Probably not, but perhaps PJ2, CONF_iture or Tubby Linton will comment. We are told that AF447 had a benign CG of MAC 29%, even with fuel in the trim tank, but it would be further aft in most cases. (Fuel could be transferred forward to improve pitch stability, but surely not until the aircraft was in stable, level flight.)
Mr Optimistic, quote:
"...the contending theories being the a/c flew itself under its own logic
or that the a/c dutifully obeyed the sidestick inputs -made for whatever reason."
[my emphasis]
The two concepts are not mutually exclusive. There is no evidence that the sidestick inputs were not "obeyed" according to C* logic. But once the aeroplane had approached the stall, due to the removal of high-AoA protections, this logic became unhelpful.
There is also no evidence that the PF made determined, sustained efforts to avoid the risk of stalling during or after a climb of 2500ft that seems to have resulted from his own sidestick inputs. We may never know, of course, what his ASI may have been indicating. But, on any jet transport, a rapid climb of 2500ft from near the optimum cruise altitude inevitably leads to a serious loss of airspeed, which can only be reversed by immediate descent towards the original altitude or lower. It's an energy thing, and flying jets is all about energy management. Perhaps the standardisation of V-NAV has lowered awareness of that in some parts of the profession. Here's one old fart who very much hopes not.