Admin, how do you protect the platform user from a scam apart from the reputation system? this is an important question.

Hello!

What kind of scam do you mean?

For example, a seller can sell a substandard or counterfeit goods.
or the seller may not send the goods.

Read the white paper (not very detailed read so I might have missed something). Seller will not receive payment if the goods are not of high quality.

Logistics is a big part of the world's problems. Most optimization aproaches use the centralization aproach (distribution centers).

I see online supply chain to be a great use case for blockchains, but at a scaled level, you will be looking at 1000s of transactions per second.

Hey! Sorry for interfering but i can't really understand why do you think that blockchain can solve all the problems you re talking about?