The thread has answer all my question! I was just wanted some input on the topic.

I have tested driving the mosfet gate with 5, 12, and 50VDC all three work. Right now, I use micrel5020 to drive the mosfet with 50VDC which will be changed to 12VDC.
I was thinking, i could probably save some money and remove the micrel part and drive the mosfet from a 8051 pin. However, I don't like the idea of connecting MCU pin to the mosfet without having a buffer in the middle like micrel5020, hc245, Inverter, or opto-isolation.
I now realize that driving the mosfet with 5VDC whether the voltages is from the MCU, buffer, inverter, or opto-isolator all will work but they could have a harmful effect on the mosfet over time.
I personally have not notice a heat problem with 5VDCs driving the mosfet. I don't believe heat will be a major problem in this application because the MOSFET will probably only be active for 60 seconds a day and probably only 12times a day. But, I will error on the side of caution.

Do you feel that buffers like the Micrel5020, 74HC245, and inverters that are driving mosfet need to be Opto-Isolated and diode protected on the MCU side of the mosfet.