The GMs make sure of that.
I've been on at times when there are no GMs for long periods. Hopefully in the future there will be a whole lot more of you on 24/7 so the general populace won't be made felt to be left out of the loop.
And as "official" as they may be, they are still an OOC source.
The guild language restrictions won't be as bold as to be bars to be measured up to. That will be too easy to correct via staff enforcement. No, the lack of RP because of language barriers will isolate those that know it from those that don't. Eventually the players(not characters) will migrate to guilds that they can enjoy RP'n in. Ones that speak a common toungue.
You'll be more that happily allowed to join a guild but then you realize that most of the RP is in a language you can't comprehend, you will most likely depart on your own. What would a Russian RPer with no english comprehension do when he stumbled on PS. he's savvy enough to download, install, and run with no glitches. Now he's here for the RP and finds only english, does he stick around and hope someone will speak in russian or will he leave frustrated with the language barrier? same thing with these race guilds,
people will join cause they picked the same race, see that they are excluded from RP by the language, and leave it. these language/races guilds will eventually become isolated, Primarily through ooc knowledge that they exclusively speak in a foreign tongue. Eventually there will be those that start to question and form their own language guilds, except these will be based on RL. Like the others, they won't exclude any player from joining but will eventually drive them off by the shear lack of social exchange.(RP and other wise)
These are not "Horror Scenarios" out of fiction, I've seen this happen in other MMOs and if left unchecked, it too will happen here. Not over night but through gradual and long term means. Good luck.