I think it should be possible. As a reward for finding and equipping all the items that will add a certain stat to 100%. Otherwise what's the point in collecting rare artifacts if they're weak not only on their own but also when put together? Being able to raise multiple things to 100% on the other hand... eh...
So basically, what you're saying is that anything short of being UNSTOPPABLE is weak? Because 100% chameleon makes you unstoppable as it basically has the same effect as invisibility except it doesn't go away as soon as you attack an enemy or interact with any object or character. It's possible to have a middle ground between that and being completely worthless, you know, and the proper balance is somewhere in that middle ground. You should be able to make powerful characters, if you find good enough items and develop them properly, but they should still not be invincible. As I said in a thread about magic supposedly being overpowered, I do not believe it is like that, as a whole, but there are certainly certain spells that can be overpowered, chameleon being one of them, and to adress that, it should be impossible to get 100% chameleon, I'd also say that it shouldn't be possible to get 100% in resistences and reflection or absorbsion spells through magic, however, I'd still say that it should be possible to have it as inate abilities of certain races or creatures, because it's kind of odd if say, a Flame Atronach can still be harmed by fire, but being able to become completely immune to all magical attacks by using the right items seems a little overpowered.
These could be in perks because you would then need to leave something out. So for you to be able to achieve 100% in something like reflect or absorb you would need to discard something else.
And what would you have to discard to do it? That won't solve anything because unless other perks are equally overpowered, people who want unstoppable characters would gladly sacrifice a weaker perk to be able to do have one, and if the other perks are equally overpowered, than you're essentially giving players the option to choose between one unbalanced feature and another, which doesn't exactly solve anything...
I mean does anyone really think it is fun to chop down people who doesnt even retaliate anyway?
If these forums are anything to go by, it certainly seems that way. Either that, or for some reason people just have a really strong desire to make the game boring for themselves.