Caution scrap after only 3 months

The scooter made at first glance, a good, stable impression.
However, as a precaution, I checked all screws are tight, I realized that it was all tightened loosely, even the wheels were not screwed tight.
Then have all tightened and thought, now everything is in order.
Meanwhile, after only 3 months of the quick release is canceled, to open the bolt and fold appears to have been lost and the quick release's fold only a backup for accidental and has not endured.
The scooter has been used by a child with 40kg, am just glad that nothing happened