So basically my idea is to change the last class to a new class:
Allrounder/Omniknight (or any fancy name)
This class has
-55 str/dex/vita/int
-is able to use all type of gear
-got all abilities blue-needs lvl 87 to reach mq (can be debated ofc)
short explanation55 int is 20less than warlock.. but with the higher vita count it would be about as good as warlock in casting
110str+dex is 20less than headhunter.. but with higher vita count it would be about as good as headhunter in melee
the endgame wouldnt get boring as you would be able to use different weapon sets/ play as caster/ melee/tank/hybrid, etc.
needed change after the first change:as we dont need 2 classes with 6 doors obviously there are several options:
a) make alchemist 5 door class so we have 3 times 5 doors to pass or

make alchemist 4 door class and switch position either after paladin or after monk (i woud not suggest after ninja or you would have warlock directly after alchemist which are 2 casting classes)
longer mid game:
to eventually increase the time of the mid game a little i would also suggest to make paladin 4 doors. this would increase the time on paladin (tanking class) so the long robe class strike (monk/alchemist/ninja/warlock) wouldnt be as bad. it would be even better imo to put paladin 4 doors after monk. this way it would be easier to have a tanking class (paladin or later headhunter) in the group.
overview of the new classes:
feeder (2 doors)
samurai (3 doors)
monk (4 doors)
paladin (4 doors)
alchemist (4 doors)
ninja (4 doors)
warlock (5 doors)
headhunter (5 doors)
omniknight (6 doors) --> reset
just let me know your thoughts about this idea or give us other suggestions/ideas/...