As difficult as that was to read, I think I understand.
It works basically like Sid Meier's Pirates!
You don't level up until you think you have enough skills/items/specialists to meet the increasing challenges of the game.
In Pirates! you start at lvl1(or higher) and you can go through the entire game without ever leveling up because the way it works, you levelup by splitting the loot with your crew and you are then offered to continue as your level or get promoted.
Promotion=everything tougher, from enemies to crew morale.
But you can simply split the loot and move on as the same class.
Am I getting this right?