For me, it is hard to tell what went on from the video. Regarding the use of parts from a previously crashed aircraft, I have done that, but I have been leery about using motors, especially if the prop broke, or the motor was stuck by a tree branch while running. If I have the slightest doubt about a motor I will replace it. As far as ESC's go, that's a hard one as I know of no way to test and make sure that it is okay - again, when in doubt I replace.
I have a Tarot 650 Sport that is currently grounded as the last flight I did produced video that showed lots of vibration. I am waiting on a prop balance device so I can make sure that the props are balanced. But a problem I have that I have not resolved is that the motors seem to surge and back off during flight. I've recalibrated the ESC's and it's not as bad, but it is still there. I am using MN3520 T-Motors and 6S lipo power. The flight controller is an APM 2.6. Despite the uneven motor speed, it seems to fly okay, but it worries me....