I'm not even sure if this would be possible, but regarding Pauls recent post about making the game more appealing to new players, I had a thought regarding passing MQ and unlocking next class.
After passing your feeder class, you'd be able to choose if you want to play Samurai or Paladin. You need to pass MQ with both of these to unlock monk/ninja
After passing all 3 door MQ's, you'd be able to choose between Monk and Ninja. You need to pass MQ with both of these to unlock Warlock/Headhunter
After passing all 4 door MQ's, you'd be able to choose between Warlock and Headhunter. You need to pass MQ with both of these to unlock Alchemist
Of course GP rewards would be tweeked so the total amount of unlocking classes would be the same as it is now.
This would give people more time to get gear sets (ie if you climb with Clubs for feeder you could do paladin climbs while getting a weapon set for your Samu, and if you only have melee gear you could climb Headhunter while getting a caster set for Warlock - this does not apply to Rick the Melee Lock
)
It would add some variety to people being stuck on certain classes, making the game a bit more fun and less mundane (Anyone who has done 100+ monk climbs can vouch this)
Would make it easier to get better groups (Need healer? np I'll go Pala. Need aoe dps? No worries I'll go samu)
You would still need to pass the master quest with every single class to unlock Alch and eventually reset the ladder