I think leveling should be fairly early, but love the idea of additional levels being available for doing harder or interesting interactions. Such as new quests to add to level cap. A larger variety of new quests with various rewards would add to content.
Boss fights should offer more continued rewards, instead of just a one time unlock with no reason to repeat. More loot options and less xp rewards for boss fights, etc. We love loot and blueprints. Make these more lucrative for doing the work. It is a problem in most games, that by the time you are strong enough to fight for loot/chests, you can already craft items of similar quality, than what is found. You have a great system with the blueprints having limited crafts available and I like that you are raising that a bit on higher quality ones.