4. USB: If we choose an 8052 that has USB capabilities we may be able to give this computer a USB feature. This could be useful for connecting keyboards, mice, or just about anything else.

You can't do that. This require an USB master which so far does not exist in '51 technology.
Cypress has a USB master chip, they are in the process of generating free code for that will interface via SPI/UART and another interface (I have forgotten which). It was schduled to come out in September, I do not know the status. This chip sell for ~$5 in 'my quantities'

Erik