I received my MA2 a week ago. It's already had 2-3 hours in the air and haven't had a single issue with it.
Previous to this I had a Mavic Mini that I returned because of major issues with connection quality.
In my experience, the MA2 is a great drone for the price.
Because the screws are so small the best options would be Loctite 222 or Loctite 425 (which is low strength, but safe on plastics). To apply, just use a toothpick to put a tiny amount on the thread of the screw.