Yup, I agree. The last time I did this (I was supposed to go LAN - DTW - MSP - SLC and went LAN - MSP - SLC instead) I ended up with about six hours in MSP and took the bus over to the MOA.

When you get back from to the airport from MOA just go to the orginally scheduled flight - since you already have a boarding pass (which you should have gotten in CMH) you should have no problem getting on. Just to be safe, though, you might reconfirm your LAX flight right after you get to MSP - before going to MOA.