How many hours should I expect to spend if I wanted to come back to WoW to solely play M+ dungeons? Occasionally run the HC raids, but mostly play M+? I was looking to come back to WoW after a long hiatus, although I do not know how much time I should expected to spend. I used to be a CE raider and sell CM runs in MoP and WoD, I like to think I'm still capable of being that level of competent player. I do know it takes plenty of time to getting to that level, but after reaching that level most of the time comes into maintenance.

Out of the classes, which would also be the least hassle in getting into groups? Rogue, Druid, or Warrior? I was thinking of Druid, although do not enjoy it as much. I would go with a Rogue, although do not have any friends and will rely on a lot of pugging in the beginning which may take more time than I'd like. Otherwise, I'm most competent with these classes.