If you have the floor raised above grade it is true a steep approach can make it so the coach will hit the door as you go up the incline. Simple solution is to make the ramp much longer thus flattening the angle. You can draw this out to scale easy enough. Do keep in mind that pulling in and backing in will create different situations due to overhang.
My dream garage would/will have a 20 foot ceiling with a high lift door and a safety track to clip in a harness for working on the roof. I had not thought of a pit myself, not sure if I'll plan that in or not, depends on time frame, the older I get, the less likely I'll do any heavy maintenance. In the end, my 'Garage' might wind up being a shed with canvas sides.