" Will they ship their orders? Or some tricks that can make money without delivering orders?"

The scamming sellers will do both, and it is unusual for you to spot them. Most are foreign nations who work in large groups. They know what they can list with no approval and listing under thousands of different products at the same time. They sell a few, then zero out the inventory.

Amazon's Buyer Abuse Prevention Team actively seeks to identify these sellers. It could be helpful to to report the sellers.