Except that's not whats actually going on in your scenarios, in your given scenarios all you are doing is adding bonus powers on top of the broken ones and saying that fixes the broken ones when it does nothing to effect the broken ones really.
The conversation was based on fixing the ineffectiveness of individual skill levels not adding any sort of effective increase to your character.
In your gun example, adding in bonus weapon accuracy every 10 levels would just mean that 1 point of accuracy would have to be removed from the natural increase in accuracy one gets from every skill level, in order to provide a bigger bonus to accuracy every 10 levels, while still keeping balance.
At that point, why not just reduce the skill to 1-10, since those 10 levels are the only ones that offer a bonus to accuracy large enough to be noticeable? Or better yet, why not just remove the skill entirely and make a 10 level perk? The 10 level perk achieves the exact same thing as the skill is doing now anyways, offering 10 levels of increases to weapon accuracy that actually matter, now you just removed a "skill" that had no reason to exist anymore, and merged the effects with another system, whilst still keeping all the same gameplay mechanics as before.
Keeping the skill at that point just becomes "for the sake of having skills in order to maintain a traditional looking character system" rather then "because skills are actually needed or do anything", and that is just pointless.