T Mack,
Welcome to Michigan Law 101. The above advice is accurate. "Federal Buildings" such as a branch of the Federal Reserve, Post Office, or Department of Defense headquarters are off limits per Federal Law. Michigan Court's are off limits due to a Michigan Supreme Court Ruling. Many will argue what the definition of a "Court" is such as whole building or only courtroom, but good luck arguing, just stay clear if there is a court attached and you will know you are safe.
Those places aside, you can legally openly or conceal carry your handgun in all Pistol Free Zones such as schools. Your CPL law (forge the back of card, it is so misleading it is scary) says you can not conceal in places such as a school, daycare center, but it does NOT prevent you from openly caring in those places. I rarely do it (election day is a good exception in my book), and I do not recommend it, but open carry in a public school is legal according to Michigan laws.
This is discussed and cited all over this and other websites, but for your verification on this topic, I suggest you start by reading a Michigan Police Legal Update on this exact matter.
http://www.michigan.gov/documents/msp/MSP_Legal_Update_No._86_2_336854_7.pdf
They have written that fairly clearly and accurately. If you still have doubts or questions on the subject, feel free to ask away. Better to sound like a broken record asking similar questions then to be wrong on a subject, we are happy to help.
In regards to "What to expect?" When I open carry I expect to enjoy my day and get my errands done and perhaps answer a few simple questions from the general public. I expect to have any police officers who see me to stop and say Hi, as I know almost all of them and it would be rude to ignore me. Yes, you may be stopped, and if you are it is in your best interest to not answer questions as if he stopped you he is probably trying to hang you out to dry, but use your judgement. In the end if stopped, you will typically hear a lecture on the poor children seeing your gun and then be on your way. I would not expect to be stopped at all though, as many before you worked extremely hard and paved the way for you.
If you happen to come across the rare untrained and illegal stop, it would be highly advised to carry a recorder with you to protect yourself from any mistruths about the situation that arise. Quite frankly, there are a few bad seeds in the LEO business whose only interests are their own and not the law, but most officers are not like this, and most have been well trained and enforce the law and not personal opinions.
-northofnowhere