Hoi,
I would be really pleased when you "prove" that the requirements for languages like these can be met. I would be positively happy.
My advise make it a project with clearly timed goals. As to localisation the first objective is 50% of the most used messages. This is where the localisation update may kick in and where you get the messages in the incubator. Do not forget to localise the Babel extension. It makes a big difference in the use of Wikidata.
When you start writing articles, Do whatever you like but from a demonstration pov do include a set of connected articles. Particularly about the own language and culture. Do reach out and do ask people to write about the subject they care about.