This is occurring in a lot of Cherry trees in my neighborhood. I also noticed it in a Bradford Pear that was right next to an infected Cherry except the BP leaves were black. I am guessing that it is Fire Blight but welcome your opinions on diagnosis and treatment.
Send a sample to the Extension Office. I've seen it on a lot of cherries in my area. Does not seem to be harming the trees. All the trees are pushing out new growth.
That last picture is scale. Not sure the rest of the pictures are related to that. Fire blight does not sound unreasonable. There is also something chewing on the leaves...but that is the least of concerns, doesn't look like it has caused any issues.