Q:
Multiple guild and chat
Yes you are correct. You can only talk to the guild you are currently representing as shown by having only 1 guild chat option, which is pretty dumb.
The only way to talk to both at the same time would to represent on and off, that would be such a pain though.
Forever proud of Union
https://forum-en.gw2archive.eu/forum/game/players/OPERATION-UNION-Bringing-Players-Together
https://forum-en.gw2archive.eu/forum/game/players/OPERATION-UNION-Bringing-Players-Together
You can be member of multiple guilds. But you can only use any guildfeature when representing that guild.
So same goes for the guildchat.
Arise, ye farmers of all nations
Arise, opressed of Tyria!
Arise, opressed of Tyria!