X2 NO, nothing on the roof of a MH!
For the spare:
They sell many different bumper brackets for the spare tire.
This is the type I used on my first Class C, which in my case also gives me a place to hang my dogs ex-pens and lawn chairs. It's both a bike rack/spare tire
And if you are not towing a toad a simple cargo carrier out the back of the MH will hold any extra items you might have.
Since I added a toad the cargo carrier now rides off the back of the toad. Provides an ample amount of extra storage space.
you can find the cargo carriers at Tractor Supply for around 50 bucks. They hold up to 500 lbs.
We must be willing to get rid of the life we've planned,
so as to have the life that is waiting for us.