First, becuase Cedar Point is vurtualy an island and since a tornado will most lilkely approach it form the sothwest, it will have to cross a large area of water. The water most likely will weaken the storm, to what degree I don't know. I am guessing since the winds will be crossing at deferent direction's than on land (known as wind sheer, which is a primary ingredient in tornadoes) it will dissipate. However, Tornadoes have been known to cross the Mississippi so one could make it over, but Lake Erie and the Mississippi are different in many respects.
My guess is the odds are greater for a waterspout forming and reaching CP. Since the winds above CP are pretty much the same as over the water, once it hits landfall I doubt it would hardy weaken. That said, most Waterspouts are only F0 or F1 which do hardly any damage.
If one of these were to cross the water and hit CP, my bet is it will be very week , 100 MPH at the most
Since the coasters are pretty much just support structure, I doubt anything would happen to them. Some roofing may peel of the top of the buildings, light objects may get bounced around, and some trees would loose some branches. CP probably wouldn't even loose power.