This suggestion is simple: make an world only for testing (or one for NA and other for EU).
It’s like almost every other MMO out there and you will get feedback from players interested in improving the game instead of releasing things in beta mode on the live servers (happened to Temple of the Silent Storm).
This way, you can avoid people raging about issues when new things comes up (like load screen bugs) and release content more reliable.
~ The light of a new day