You forgot the biggest issue... EVERYONE has "Cunning Action: Hide" from the get-go.
I'm sure this is the DOS2 engine DNA showing through, but they really need to fix that.
I managed to solo the first three brain doggies without taking a point of damage on a Warlock simply by getting to just outside range and then doing a: move into range, snipe with EB, move out of range, hide (which I shouldn't have been allowed to do).
I was going to try a Rogue, but quickly realized (playing other characters) that there is really very, very little advantage to it, or, even any point (if the sneak attack damage is bugged as you say).
The point to playing a Rogue, is that you WANT to play a Rogue - Roleplaying game etc? You indicate that you are a min-maxer type of player <nothing wrong with that>, but Roleplayers don't pick a class because it's FotM. We only have access to 4 levels at the moment, so we don't know what Larian have in mind to how the Rogue <or any other class for that matter> will flesh out. I'm sure Larian won't have any class that is pointless in playing.