So, your changes to Super Reflexes seem super overpowered unless you lower the defense values, which, to me is a nonstarter. SR is about dodging, so it should have high defense.
Also, turning the mez protection into an auto power? That just sounds crazy overpowered. I could see an argument for turning it into a toggle, but there is a trade off there, in that it could no longer stack with itself.
Finally, I disagree with you that SR is particularly endurance heavy. It has 3 toggles and 1 click that is used regularly. The toggles are not higher cost than other sets and there are fewer of them. The click power actually works out to be less endurance per second than a similar toggle.