How do you become a tester?

In the group can the testers play when the game is closed?

I Believe They Can.

Does anybody actually know how to become one though?

They’ll probably publicly announce it that they’re having test applications, but for now I guess they don’t need testers.

you can’t become a tester right now since I guess they have enough of them
it doesn’t really matter since next week the paid-testing starts which will let you play the game as much as you want

I Agree. Paid Access Is Super Close. Though They May Still Close The Game If There Is A Serious Game-Breaking Bug/Exploit.