You are contradicting yourself quite a lot. You can't have staff/admins and being decentralized at the same time. Having someone moderate the content is the opposite of decentralization. Same goes for Tor hidden services or servers in general, you can't have those as well. I suggest spending some time researching the terms etc before starting any project.
I added this:
Today is the 1 Nov. 2021 22:01
Last bitcoin block: 00000000000000000000c0b572b62748dbc6c0611add60eac2022959c9f04381
This wont be a decentralized marketplace. The goal is to create a fair and most community ridden with just a little help from the staffs (admins, moderators etc.)