Is it okay to connect directly power supply to usb 5v? ++ & - - to maintain power?
You can't extend USB with cat5e cable. It is not rated for the required current for USB 5V power, and it has 100 ohms characteristic impedance while USB requires 90 ohms. It is also not OK to parallel your 5V source from PC with a 5V power supply, most likely you end up frying your PC. Buy a 5m USB cable.