Standard point buy for 5e.
For traits, as I think I said in the document I'm actually looking for players to give me a bit of guidance on what sort of things they would usually want from feats or magic items for their characters. That will give me some direction. In addition, skills, languages, proficiency, expertise, possibly even specific character mechanics.
For scholarly languages, I think Kûnüric is probably a good one, but it's mostly lost. It is known to some specific scholars though... for certain specific reasons.
Atrithi and Sakarpic might be important, as they are languages from the oldest regions ruled by men that are still standing.
High Sheyic is an incredibly important religious language to some cultures, and the language of the Ceneian Empire. That empire was sacked some 300 years ago, but it's still an important language.
These are all languages of specific nations that could come up:
Conriyan: Language of Conriya.
Nroni: Language of Nron.
Cironjic: Language of Cironj.
Cengemic: Language of Cengemis.
Sansori: Language of Sansor.
Ainoni: Language of High Ainon.
Zeümi and Scylvendi are significant in that those two cultures (one a powerful nation, one a pastoral people known for their barbarians) have their own specific language. That opens up a lot more options for trade or such.