Three Questions about Klaf

I was given a mezuzah case with a klaf in it. The klaf seems to be old and some of the texts are not sharp anymore.

1. Is there a way to know whether a klaf was printed or handwritten?
2. How do you check whether the klaf is “kosher”? If I have to bring it to a place/rabbi, is there a fee to do so?
3. Why is it important to have a kosher klaf in the case? Is it coming from the fact that if we have to be reminded of the sh’ma and v’ahavta, then the the writing should be accurate and complete?

Thanks!