The first one just feels like a premature optimization. Yes calling setCount forces a rerender of that component, but unless there's lots of subcomponents inside that component, I wouldn't bother. Chances are later you'll need that state in the view, and if you have "unexpected side effects" from rerendering then that is the problem.
The other tips are fine; effects should have a single responsibility and links and buttons should be accessible.
The other tips are fine; effects should have a single responsibility and links and buttons should be accessible.