The problem is, to use it right. In the theory, it sounds awesome but in the real it doesn't make sense...for example
5v5 [Small scale PvP] one Team has a spy, he need between 4-7 seconds do gain 20 stacks...then he jump....and is dead. Why?
Your Team is (I hope it) not full of idiots, after his first skills they all know his specc and his intention to Burst someone down.
After he raised 20 stacks, he has 30 seconds to use them or they are gone....you have also a Timewindow of 30 Seconds...in this time he COME...doesn't matter where you are, he would like to come and burst. Your Team get a bit in the devens and after a come out of stealth he would get to kicked, stunned and get killed.
This is the reason why the warzone [the 5v5 battlefield] was the best thing for the PvP in Korea, many Spys left the glass cannon build and get more devens spells or respec the class....cause your K/D goes down to HELL!?
It is nice for solo roaming, but for more it is kinda useless.
The other Point is the time you can get cc'd by a hermit, yes it is pretty long but not strong. The reason is, other people can interrupt you or can disspell your CC or do it easier.....kill you XD
You did a nice job with the Theoriecrafting, but this game is and would never get balanced in 1v1 - 3v3 NEVER!? It is a Game based on High-Scale + a bit on small Scale, also you need to thing to another points