Tell me about this rudder-lock issue, can't say I've ever heard of it. May be just fading memory.
The worst swing I ever had from ailerons was on the HP7. Depending on the idividual aircraft, it could yaw in the opposite direction to the aileron input. It was a little like that on the Dak, but not as bad. The flying was really quite basic, even if in slow motion.
However, this thread makes me a bit concerned about the number of times I've had the rudder on full lock, while side-slipping into tight little strips. It behaved very well under those conditions, and came out of the slip with a graceful yet controlled swing.
While on full rudder, the airspeed could be puller right back to a figure that would give astonishingly low ground-speed while in brisk surface winds. It would give the impression of being in an elevator.
Ailerons were indeed very hard work, or seemed so, having come back onto the DC3 from a frisky early phase 1-11.
First time round I was P2 to guys that had flown it 'Over the hump' and in other rather demanding conditions. I recall being somewhat surprised that it could be made to do the things they did with it. Not too many rules about then...well, not ones they cared to abide by.