12/04/2014 11:49 is a piece of work. Ignore them. I think s/he may just be a troll who likes to get a rise out of people. Or, if they are legit, s/he clearly has limited experience w/ toddlers. Unfortunately that's my only advice for you. Advice like 'tire the kid out in the morning' is completely unhelpful, you've done all the obvious things. Some kids are just higher strung, more stubborn, higher energy, more persistent, etc etc than others. From what you say, seems like MB is ok w/ the behavior, so I wouldn't focus so much on changing it.The only thing I'd look to change is the requirement that you sit in the hallway while it happens. Ask the mom if she can get a different baby gate, one that the child cannot open - or in some other way contain the child for a brief time so that you aren't tied to the hallway. I know I'd be driven mad in that hallway.
Then I'd look for a different job. Kid sounds like a nightmare, and MB isn't much better.
(i'm an MB, not a nanny)