I think the proper way to do this is through the skills system with an 'competence' value for many skills, altered by class. In this case then, all new players would start out with all skills, but some would be marked unknown. (flag unidentified can be used here.)
getting a scroll of a skill would give a chance to gain some competence in the skill, rather than the all or nothing thing currently. Each class would have a maximum competence, which would be set on choosing a class. in the class arch there would be the inital competence also.
Whenever experience is gained, this is multiplied by the competence, so skills which your class is competent in, can take forever to level up.
example, let's have the player be a barbarian, they may have a max competence in alchemy of 0.5 (say). It is initally unknown.
They find a scroll of alchemy, they read it and have a 36% success (rolled between 5 and 95, biased for high INT), they then learn the spell, and have a current competence of 36*0.5 = 18%.
They make a water of the wise, this would normally give 1000 exp, now it gives 1000*18% = 180
they get another scroll, have a 60% success (lucky roll)
they now have 18+(60*(.5-(18/100)) which is 37.2%
They make another water of the wise, this time they get 372 exp from it.
For an alchemist, their max competence may be 2, and they might start with 1.4 (say).
immediatly making a WotW will give 1400 exp.
they can get a scroll of alchemistry, and roll 40% (for example). they would then have 140+(40*(2-(140/100))= 164%
now a water of the wise will give 1640 exp.
In this case then, all classes /can/ do anything as before, but some are better than others at different skills, and choice of class should remain fairly meaningful for far longer.
the 'expmul' value was mostly intended to do this anyway, It needs relatively little modification, except to archetypes and a little bug checking to have this work on new players/servers.
For existing players/servers a patch to change it wouldn't be that hard to do technically, but it might meet some resistance
