Can I use just an USB port connected directly to a PSoC 5 chip to use the bootloader/send a bootloader file from PSoCDesigner/Express?
Check out the below forum thread on bootloader for PSoC3. PSoC5 also supports the I2C bootloader. USB support is not yet available.
However, there is an errata for PSoC5 bootloader. The PSoC5 bootloader only works at 400KHz I2C clock. It does not work at 50KHz and 100KHz clock speeds.