I can’t find any reference to this in the game manual.
Will a low hang be counted if the robot is touching the field perimeter or the bar’s bracket?
You aren’t allowed to put pressure or anything on the perimeter, so probably not.
I was thinking of building an accent device like the ones used in the 2013 FRC game Ultimate Ascent (or even our own RoundUp), where robots were required to ascend a large pyramid type structure (be it, that was tilted and had rungs that enabled human style climbing). But if anyone is interested there were some pretty awesome ascension devices. 
It could help with some inspiration for this years game. Without the side rungs through (if it is illegal to touch the perimeter), you could have issues with stability.
This does not make sense seeing how high hanging will put pressure on the field perimeter anyways and make it support the weight of a robot
They’re saying that high hanging shouldn’t put pressure on the field perimeter.
Having done FRC for 4 years, I think the best end game year to look at was 2010 Breakaway, a lot of teams climbed on the vertical poles. Here’s what one of the teams did using a lot of stored energy, there were a lot of others like it.
So can you apply the weight of your robot to the pole? That’s what happened in toss up and Round up.
I looked at the bracket where the pole is attached and it is metal. If you look at is as the pivot point then the bottom of the pole will be forced into the corner of the field.
Yes you can, you just can’t use the field perimeter to support your weight.
Actually you can, there is no rules against it, just not leaving it is the problem