One sure way to get results from dealer would to be load the thing up and swing by your lawyer and give him a ride to the dealer with you. Explain whats going on and ask for a possible turn around on repair. Let your lawyer take notes and such as this looks to be litigation in the making.

Watched your videos and sounded as though i heard what sounded to be the brake rotor chattering. Possibly the air gap is not correct or disc binding. Also the acceleration rate can be set forks leading and trailing. Being it as a rider platform, the high speed latch could be the problem.