From hearing the stories about ZZP PCM'* running lean and blowing engines up, I am really looking into getting a custom tune. I have never and nor do i know how to check if im running lean.

Does anyone know a shop in michigan that can give me a good custom tune?

A good way to check if your running lean or rich is be hooking up a 5 gas analyzer to the tailpipe. you can see if your running rich, lean, have a misfire condition, combustion chamber temp, along with other stuff. a five gas is a great diagnostic tool.

5 gas analyzer are expensive, if i am right they run around $3k

You could also pull the plugs and read them.
Use a fuel pressure gauge to see if pressure is correct
Or monitor the O2 sensor in the car.

You can use a, wide band O2, a bit pricey at perhaps $200 or so. Or know someone with scanning software where you can read narrowband O2 and get a average.

How do you fix running lean, and does it stop it for good?

You would need to tune for that. It'* a on going process. The seasons, temp, etc all effect the tune. I have like 3 different tunes right now and change them with the seasons.