Newly launched MMO, lots of people are trying to get it, and FPS is not part of server issue.
Sure, go back to the MMO that has been established for many years. There are a lot of people and this will pass soon once the hype dies down.
No, it doesn't work like this. You increase server size and you have worse server stability issues.
All in all, this is being worked on. No need to make assumptions on what would fix it because you will be wrong a good % of the time. Things are being worked on, just know that. Look into this in about a week and hopefully it should be dying down, if not, then that means AA is doing great and it will be addressed from there more than likely.