They're actually easier to pit when they're slightly frozen. You can process them and can them any way you would fresh, or just leave them frozen and use them that way.

I would probably leav the cherries in the freezer until you want to use them, I Think that canning after freezing will make them really soft.

They recommend peeling pears since that is where the majority of the bacteria reside. Only you can weigh that risk. Not sure what canning will do to the peels. Pear skins are softer than apple skins. I know Apple skins get tough and leathery if left on apples.