About your example, I think we can explain the fact that even if shooting is his lowest skill, it's still pretty good compared to so I think your player is too good to see the clout of skills.
We should consider a player specialized in offence or defence, however it may be difficult to evaluate skills' impact as we do not see our player everytime during a game so maybe you're right.


And about the highlighted skill, I think they gain faster :
Click image for larger version.  Name: T11.jpg  Views: 241  Size: 67.9 KB  ID: 70060
My player who have been four or five years with me
As you can see the highlighted skills is higher than the others :
For the defensive skills, it is because I mostly train him for offence
But the "agressivité" is very low and I assure you that I always begin a drill with warm-up which gives aggression
So it may gain faster