Sunsingers really didn't get that bad of a nerf. So fireborn causes your super to be shorter, so what? In PvE you're not really supposed to use it unless you die. Then for the melee situation, I think flame shield granting a potential shield won't be a big difference (we'll find out though) and it sounded like the other melees were getting a buff as well to make them more appealing. And the main problem in PvP (firebolts+burn perk combo) was left alone to not break the subclass for any game mode, meaning you still have it in PvE. It does not seem as if Sunsingers got a major rework like Sunbreakers. Unless the said tweaks were a little more drastic, you should have nothing to worry about. TL;DR- Sunsingers won't be trash, the tweak it got wasn't as bad as you make it sound