I bought this mouse today, and when I noticed this issue too I was sooo... pissed off.
I immediately took it apart (haven't even plugged it in lol) and fortunately enough a little piece of tape on (around) wheel's leg fixed the problem
The problem with these mouses is not the scrolling wheel itself, it's rather plastic mountings around it - there is too big of a cavity for scrolling wheel to properly fit in, it's just loose. Technically it's a very minor problem, but surely annoying as heck. IMO it's unacceptable how $60 mouse can behave like that, while most logitech budget mouses for $8 are perfectly silent.
The leg I'am refering to is the part of the wheel which goes on top of middle click switch.
PS.
1. There is a point on the wheel where it becomes harder to turn
I noticed that too. It's not big deal and not hugely noticeable, but I do prefer smoother/ligher scrolling design overall. In windows I had to increase scrolling lines per notch to 7 lines (was 5 lines using Gigabyte M6900) to make it more practical.