Can a hard case cause scratch on iPhone?

I have an iPhone 5 and a hard plastic case. I never actually used it because I'm so overly protective of my phone.
1. Can it cause scratches?
2. What if it gets stuck, how do I get my phone out?
3.It's pretty tight (I guess it should be, because it's a fitted hard case lol) but can its structure damage the phone?
Please let me know sincere answers.

1) It can scratch the bezel surrounding the sides of your iPhone, but only if you constantly take it on and off and cause it to scratch against the surface.

2) It should not get stuck. If the case gets stuck on the phone then it isn't a case made to fit your phone.

3) It can potentially do so if you happen to do the same as I stated in the first part, taking it on and off constantly. It can push and tug on the actual phone hardware and can even chip off some of the parts if done hard enough. It's realistically a severe case of Wear and Tear, which for most smartphones is contributed by fitted cases.

If the case will protect your phone, great! Just be careful with how much you use it

Normally if you buy a nice and genuine case, it won't scratch and it won't stuck also. But you have to be very careful about the case. And the other point is if take care you phone nicely, nothing will happen. But I'm suggesting some nice and good looking cases. If you use these cases it will not give you any problem regarding scratches and stuck. So please go and check the link and you have an idea what I'm talking about.