Given the recent lively discussion about loremaster and how much the playerbase seems to appreciate the class as a means of allowing a character to learn more languages than their INT mod would ordinarily allow, it might not be a bad ideal to allow players of other classes access to a similar feature. The best way I can think of doing this is by allowing a character to exchange skill points for language slots by way of a new skill.
There's some PnP precedent for this. 3rd edition D&D allows characters to purchase new languages for 1 skill point each through the "speak language" skill (see: 3e Player's Handbook, page 74). Because most of 3e is geared towards lower level adventures, rather than a setting where everyone hits epic levels, the exchange rate would probably need to be changed for Arelith. Additionally, because simply trading skill points for known languages would sidestep the language learning system, it would probably be best to allow the skill points to be traded for language slots, rather than automatic fluency.
I would instead propose that a linguistics skill give 1 extra language slot per 5 hard ranks purchased. If you wanted to get fancy with the skill, it could also provide bonuses to learning speed or teaching speed, but I believe it would be a popular choice even if all it did was increase language slots.
I would also add that, because Arelith currently has so many competing, useful skills now (I can't remember the last character I played on which I could buy all the skills I wanted), these languages slots will be purchased at the expense of some other nice-to-have feature, like search, sail, ride, etc.
