Roz: a wide barrier gate has been installed with it's own ticket reading equipment, so you should be able to open the gate yourself with your ticket. I've never used one of these myself so I don't know what's to stop several people walking through.
There are only 3 'normal' gates, so the configuration is presumably 2 in one direction and 1 in the other. Unfortunately the way the ticket readers have been installed means that when exiting from Platform 1 you might need to insert your ticket in a reader on your left hand side, depending on which barrier you use, instead of the right hand side as is the norm. I don't know if that was intentional or whether they've made a mistake. If it's intentional then it will cause confusion and increase congestion as people try to work out where to put their ticket.
I don't think 2 barriers in any one direction during peak time will be sufficient, given that everyone will have to pass through the barriers because all the other exits have been closed.