The pumps work great. I haven’t had one problem with them at all. I have only run 8 misters off of one pump so idk the max number you could run. I run one pump per cooler. You just need to keep the water pressure at 100 psi so the misters will produce the desired droplet size. If it is to low the misters will just spray a small stream of water.
The misters I use are the brass 0.0012 inch misters, They can be found on ebay and amazon.
So with a hole half the size of a human hair, yes they will clog up. I filter the water returning to the pump and if you keep the water clean they don’t clog up that much. Have extra on hand just in case.
If you have any other questions just let me know