Why are the VSC on/off, ABS, and Brake warning lights on randomly?

What is your question?

First I had my 4 wheel drive lights flashing so I had the actuator replaced so 4 wheel drive lights no longer appear and it functions fine. Now randomly I have the VSC off/on, ABS, Brake warning lights come on as well. I have a steep driveway and I am noticing when I give my 4runner power to make hill, my gas pedal maxes out and my tires are spinning as if my 4 wheel drive is not working and I have to back down and retry.....getting no where. I feel as if my 4 wheel drive is not functioning when this happens. Why would my 4 Runner be bogging down and loosing power, and why do these other lights randomly come on. Any ideas. I never have trouble with engine light coming on. Engine never bogs down and looses power on otherwise plowed or good roads.