The thing is though, level stops you from doing none of the things you listed, want to finish unlocking everything before entering HW? You can, your level means nothing, if you don't want to blow stuff up or be unkilable you could just go get a low level weapon and gear and control your power that way, being level 80 and doing the ARR beast tribes is no different than being level 50 and doing them, all you are is stronger, which you can easily throw away if you're so inclined.

But there's a even easier way to fix your issue, just use another class, you get two that start at 50 for ARR stuff, two that start at 60 for HW stuff and many others, if you're new and want to always be at level you can do that, but like I said, pretty much all your power gained is in your weapons and gear, want to do stuff like a level 50, just put on 40ish gear and away you go.