Hi Terranisaur!
We definitely want to have difficult boss fights to ensure that the endgame is challenging. This is something which will likely not really be seen until late in the alpha or even the beta.
We don’t plan on having roles such as those. Typically either healers aren’t really capable of doing much content solo, which doesn’t feel good - or they’ve the same damage as everyone else, so everyone plays healer because they’re superior. Some classes (Paladin’s a good example) will have more utility than others. There’ll definitely be ways of helping your team, but not to the extent of an MMO’s healer.