As usual I am going far off in the weeds here. I believe there is no such thing as a the most difficult power tool in the wood shop. Yes there are many tools that are hard to handle / use but that mostly comes down to the brain power or lack there of someone put into the tool when designed, cut a few corners to fit a market and the brain of the operator.
All power tools have rules we all know them and we all violate them regular.
Routers used with dull bits or pulled into a climb cut when we know it has the capacity to go all wrong.
Shapers that are used by an intimidated operator ( I would guess that is all of us to some degree it sure is me big time scares the crap out of me !)
Jointers oftetn used without blade guards and work pieces fed through without riding the fence
A tablesaw just because we use one so often we get complaicent and too comfortable, especially when there is a dado blade installed. In the UK & Europe if you buy a tablesaw it is deliberatley fitted with short arbors to prevent their use.
I use a 12 inch disc sander and can't tell you how many times I left skin and blood on that 80 grit monster just because I was lazy, stupid and in a hurry.
So all power tools are dangerous even sometimes before we plug them in.
mike calabrese