+e stands for except which excepts users from the channel who match a hostmask in the banlist allowing them to join. When a hostmask is set in the except list,the mode +e overrides the ban on the user that matches the hostmask.
In the above example, let's say there is an existing ban is set with the hostmask *!*@*.my. PJKevin's hostmask is PJKevinemail@example.com. PJKevin will be able to join #peanutbutter because he has an exception with the mask PJKevin!*@*.my.
A channel half-op has the ability to kick people from the channel unless the people are opped or voiced. In addition, they are able to change channel topic.