You do realize you are just opening yourself up to all manner of comment. Ultimately the game is in EA and for many people the best approach would probably be to set the game down and come back when it is in 1.0.

And you have not yet killed the boss so I guess you will really get 3 nights of play.

But to your point on leveling, even in lower tier biomes you could never fully level all that biomes gear without some resources/items from the next biome (usually needed to upgrade a crafting station).

Given that we have some biomes yet to come I would guess the next one will have what you need to upgrade crafting stations so you can tier up Mistland gear to max.