Is there any rule against blatant racism if it is a guild chat? I know you can just leave the guilds if you don't want to see what their chats are but it's still unpleasent seeing racism anywhere. They also spam invites to their guild so it isn't easy to avoid.
Yes there is, and you can see more about it and the others over here. Just open a GM ticket with evidence of whatever they're doing and wait for it to be handled. There's more information on reports over here too.
I honestly don't care about the BS in chat, people try to just piss someone off, they're edgy, let them blow it out, but what's annoying is the repeated invites to those guilds.
Ohdo on horde used to be annoying, but Alliance has that HOPE and it's variations ("H O P E", "H | O | P | E", "HOPEFUL" etc) where chat is just filled with BS exclusively. That should be bannable for sure, 10/10.