Hello,
It's true that when a spring is fully wound you will feel it as a strong resistance of the crown ,on a manual wind offcourse .( overcome that resistance and you can visit your watchrepairer...)
As you know an automatic watch is wound by your movement.Because the mecanism doesn't know when it's fully wound there are different methods of " saving " the spring ( or teeth from the wheels) from breaking ; most popular is by means of a sliding spring at the outer end of the mainspring, this short spring is much thikker and stronger then the mainspring but soft enough to slide under too much power from the automatic system ( or you winding manually )
So a fully wound spring will slide inside its barrel , making some extra noise ( you've got good hears ) nothing wrong with that.
Harwood had a different system, and once I had a JLC in repair with another system ; it had a normal spring but there was a system which disengages the automatic system when the spring was fully wound.( nice system , but the last teeth have a hard time , you can imagine)
Is this clear enough?
Greetings and enjoy your automates (?)
PS ; when you feel/hear the sliding spring sliding its no use winding the watch further , the spring is fully wound.
And yes there is wear and tear inside the barrel , but with regular maintenance the watch goes for centuries.