Sure!
1. More likely a cache/timing issue only. It actually works when the user is not logged in, so you may have accidentally checked the user was not logged in or it was cached to that somehow.
2. Well, it could still work, but you may have to check the bbpress documentation for that. Sometimes some functions are moved around or excluded from certain hooks.
3. No, I enabled the WP_DEBUG in the wp-confing.php for a minute to see the errors pop-up on the screen, and this was the only error, after which the script terminated as it should.