screen replaced

I suggest that you make a Genius Bar appointment at your local Apple Store or Apple Authorized Service Provider to have then take a look and provide you with your options. Normal "wear & tear" would typically not be covered, but it will be up to the Apple technician to confirm the extend of the damage.

As Tesserax pointed out the OP needs Apple to look at it, if they determine it is cosmetic damage they will often refuse to replace it even if the OP wants to pay for it. They will also refuse to replace batteries that haven’t reached 80% unless a diagnostics test shows other problems.

Sure. I don't believe there's any particular reason necessary as to why you need a screen replacement, as long as you pay for it.