You were asked to turn the Kindle off but chose to turn it on again, that's wrong.
I know zero about the ins and outs of banking, building, etc so would never pretend to tell somebody in that industry how to do their job.
Sadly, many passengers feel they know the airline industry far better than those who work in it every day. So, unfortunately, many passengers prefer to make their own rules be it on board or on the ground. Oh well.
As for what the Purser said I wasn't there so I'll refrain from comment.