On the language thing, I figured it was a bit along the lines of;

Universal common tongue = English. 

I mean, the Nexus gates have obviously been around for a while, and everyone knows about them and uses them regularly, so there´s no reason people haven´t traveled through them all and inadvertadly created a common tongue.

If we use that as a default, then it becomes much easier to create characters who don´t know the universal common tongue. Just because it exists, doesn´t mean everyone bothered to learn it ;)

On that note; Faction idea. Nexus Police.