On occasion I'll toss a cure to another player who happened to get hit with an AOE but unless the tank isn't doing their EXTREMELY EASY job of keeping all monsters focused on them, I should never have to heal another player.
I stopped reading right there.

Have you done anything past level 40ish? Because from what I have encountered so far, is that there are a few encounters where there's some damage that can't be mitigated by stepping out of the red spot on the ground.

Also like someone else pointed out: time sinks does not equal a harder game. (Not saying this is really difficult before hardcore end game stuff.)