Regarding screen size, resolution and multiple wireless mouse receivers.
I have a 24” as main and my extra pc uses 19” x 1, 15” x 3. Where the 19” has a other native resolution that the 15” screens. Although the wireless mouse setup works perfectly when forcing the 19” resolution to the same resolution as the 15” have.

Not sure if I’m just in luck or what, but it hasn’t been an issue for me.

//Ztar