I'm not sure if this has been reported yet, and as much as it pain me to report because it is and awesome glitch...Barriers at tier gates can be easily glitched into. I found this out as two people demonstrated it to me while playing. I did not have the correct gear for tier 3 but I was able to pass through by walking forward (using the w key, not mouse) while a person behind me threw potions at me from behind. When I was hit straight on it propelled me through the gate. Just thought I'd let you know if you didn't already.