Alongside pear patio trees which do OK.
I think both of these articles will help with your fruit drop problem:
https://www.gardeningknowhow.com/edible/fruits/cherry/cherry-fruit-drop-problems.htm
https://www.gardeningknowhow.com/edible/fruits/fegen/reasons-for-small-hard-fruit.htm
I had blossom this year after 3 years but no fruit
This article should answer your questions:
https://www.gardeningknowhow.com/edible/fruits/fegen/pruning-for-potted-fruit-trees.htm
Is it correct that you don't have to water my cherry and pear trees that are in patio pots during the winter, and should I wrap them up
If you go for more than a couple weeks without precipitation, I would water them. You shouldn't need to wrap them unless you have sustained temperatures below freezing.
https://www.gardeningknowhow.com/edible/fruits/fegen/winterizing-fruit-trees.htm
https://www.gardeningknowhow.com/edible/fruits/cherry/growing-cherries-in-a-pot.htm
https://www.gardeningknowhow.com/edible/fruits/pear/growing-pear-trees-in-containers.htm