Mouse settings would depend on your physical surroundings while gaming.
You want to have a good mouse pad, perhaps a big one. Or get rid of it at all, and get a good table.
Everything physical will effect you first. Any disadvantages here, you go to the settings to fix it up.
I try to have a medium mouse sensitivity, so I could pick up my shots with the highest chance of hitting a target. Some people have a button that can change sensitivity to their liking anytime, so this task is easier for them.
Medium also means I have to turn my mouse more and spend more real life energy working out my hands to turn. Despite how lazy I am, this is not as bad as you might imagine.
To sum it up - everyone has their own ideal settings, so everyone should set it up themselves.