Thats the thing, yeah?
There is a difference between "hard" that is balanced and "hard" that is just brutal nonsense and right now the game is just brutal nonsense.
part of that is due to bugs, that can be written off with how early in the dev cycle it is. The other part is the lack of balance.
this game hinges on the dev's sense for balance, right now its a bit unfair to judge but with how they decided to tackle healing I do not have much faith.
rouges are indeed supposed to be hard, but I cant think of a single one that just outright punishes you for healing when the heal heals so little.