A good set of new tires, freshly precision balanced, is better than any set of used tires that are unbalanced. I may just pop for the Michelins this summer rather than suffer through another season of the shakes. I will need better tread by the time winter rolls around anyway, so it's a matter of cheapness wrt the miles left on the BFG's. That's the situation as I know it today. You will not like our response.
Explorers are great, but they really cost a lot of money, both to buy parts for and feed.
It will take you 4 years plus one additional semester. If you intend to be an automotive mechanic, you still need to invest in the training such as Community College, including the computers, to be a good one these days. After this you will need to apprentice and maybe work for a specific manufacturer or dealership. You will be a step up on most toward building and modifying any fine vehicle. When you get a decent job after all this, you need to save up one full years salary as a reserve.