Some of us don't have more than a job or 3 leveled to the cap, nor do we desire to level a dozen jobs. I for one have reached the point where all I have left to spend merits on are 2-3 remaining stat skillup and thus am not motivated to get into Aby anymore except for seal collection.
Which is itself a crapshoot but a discussion for another day.
What I would love to do is cap some of my uncapped skills. Parry. Guard. Club. Red mage's dagger.
However, joining an aby group and walking up with two clubs strapped on your monk will get you booted almost as fast as joining as 90 blm and showing up as 30 sch.
Here is what I propose:
A new merit category: Skillups. It works just like the other 'skill' categories (you can only enhance those skills that the job in question has) however, instead of increasing your cap, you can spend a flat number of merits for a flat number of skillups. Say 1 merit, 5 skillups.
As a sub note, I would mention that puppetmasters should be able to skillup the abilities on their frames in the same manner.
Just an idea...