Now you mention it, Beowulf, I had a bit of the same trouble with the rudder function a few months ago. It wouldn't go all the way in one direction when I tried to calibrate it.
I found a 'crude' solution - I levered the rubber surround away from the stick and squirted about a gallon (3.7854 litres
) of WD40 penetrating lubricant into the works in the stick base. I guess I frightened the pants off the thing, it's worked fine ever since!
On the sensitivity question, I've learned to keep all the settings at the default (60%) level or below. And to use a very light touch and small movements; same as you have to on a real aeroplane. On not very much experience of the Microsoft stick, I'd say the Logitech one has the better 'feel' of the two.
No idea about the Saitek, though; I hope someone else can help you.
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci