AllDodge: Do not know/have not read every single post on this thread, whether others have mentioned this... but you might think about the possibility that the loader frame has been twisted very slightly. It does not take much to cause the pins to be VERY tight. I have found one way to diagnose that (as well as free up the pins) is to put the tractor on a nice flat concrete floor and use a 4x4 scrap or other chunk of wood under one side of the bucket. Then force the bucket downward just a little and experiment to see if the pin gets free or not. Of course you do this on both left and right sides of the bucket in a cut-and-try process.
I am convinced that ALL quick removal loaders (no other kinds exist any more...) have some degree of "twist" that is residual, (amount left in the current position of the loader) after each usage. Sometimes a little to the left,sometimes to the right, usually very small, hopefully negligible, amount. You can verify this via using the same flat concrete floor and tractor position and measuring bucket tip height on far left and then far right. Of course there are many variables in taking these measurements and it is differential (not absolute) distance from the floor that you are looking for.
OBTW, I have mentioned on other threads that none of the loader manufacturers (nor the Nebraska world-class tractor test lab) ever seem to publish torque information on loaders -- what they will stand, how much torque it takes to produce a given amount of angular deflection, what amount of imbalanced force does it take to leave a permanent 'bend', etc.