First, in Michigan it is NOT a CPP
It's a CPL (Concealed Pistol License)
Second, the CPL instructor doesn't know what he/she is talking about.
You lose nothing by getting your CPL.
Actually you gain some freedom because now you can OC just about all the time.
Like when you leave your house OC'ing then get in your car, go up to the gasstation for a pack of gum then back in your car etc... all OC'ing (with a CPL)
Please take your time and fully read and understand this post http://opencarry.mywowbb.com/forum30/13328.html
It should answer most of your questions.