It was not uncommon for me to have at least one skill at 120% before end game, along with several skills at 90%.
But in a MMO, were there is no true end game, would (Should) it be possible to have a skill level of 200%.
What is the benefit of having such high skill level?
Remember that it costs more points to receive 1 point once your skill is at 100%.
On another thread (Survivalism), it was brought up that it might be interesting to have a 1 time choice perk (from several choices) that a player could pick once they reached max skill level (100%).
What if instead, you would get a perk choice at 120%, then again another at 150% and then again at 190%.
Also, in my mind, the need for having such high skill level would be if you are going against other players whom might also have a high skill level.
Though I have other thoughts on this, it's your turn.
Dave Chase