I don't like that you are using some new stablecoin connected with USDT token on ethereum blockchain, and I don't understand how this exactly work.
Here's a
detailed writeup of the trustless 2-way peg.
Can you please explain to me how this exchange can be called decentralized when it's available on only as web version and it's operated by centralized server?
You can
download and run the client just by clicking on the html file. The server is not required to swap tokens. In theory, I could paste an order here into this thread and then anyone could take it. The purpose of the servers is only to bundle liquidity.