The other way to change the world tier on PC is to press escape. The top menu option is WT.
Also remember that bosses build up an immunity to powers. It's the swerly symbol that turns blue on the left of their nameplate. Time those powers for interrupts.
Completed the story and I really enjoyed it. Took my time and read the lore entries as I went. The journal added a lot to the story. Was it a fun, cheesy, bmovie? Yes, yes it was. But I thought they did a good job of telling it and pacinging it through the missions.
Grinding expeditions to get good gear here I come.
Oh and if anyone hasn't noticed, there is a Guides menu option when in game
It has basic concise info on all the base mechanics like crafting.
It plays nothing like destiny. Yes it's a looter shooter but has a very different feel. It's not a live service game either. So there's the base game and then I expect expansion packs. Not a dlc drip fed over a year. I think there has been info released but I've not read it yet. The devs have been good at posting info on reddit.