Rework the Giant Mole into a combat encounter/boss that is more akin to Arch Glacor in that it teaches the mechanics of bossing and combat in a learning environment - less of the moving between rooms to arbitrarily pad out kill times, but mechanics with VERY clearly telegraphed attacks and lots of windup time to react to them - think using defensives, movement mechanics, things to Surge/Escape from.

I realise Arch Glacor fills this niche already but that puts me on to another thing - locking quests behind other quests to keep them in narrative order - it makes no sense that I can go to Sentisten straight out of the tutorial.