1. Yes, your configuration is valid
Please look at page 5 of the datasheet http://www.cypress.com/?docID=45285 for more details.
2. It is possible. I don't see any issues with the use case.
3. The USB port configuration can be done through the HPI interface. Please look at page 31 of the datasheet for more details.
I have a question about CY7C67300.
I would like to use one pice of CY7C67300 communicate with other pice of CY7C67300.How to achieve this transmission？thanks！
What is your application?
You can try communicating between the devices using UART,SPI.