Iphone 5 making own selections?

My iPhone's screen has been broken for a few weeks and I've been using it anyway while I find a cheap place to get it fixed. Anyway while using my iPhone it can start making random selections like entering a random app or something. Anyone who knows what's wrong and if it will be fixed by changing the screen?

Why can't I replay snapchats on my iPhone

Since the new snapchat update, I Haven't been able to figure out how to replay snaps. I have tried the standard 'press and hold' on the snap i want to replay, but no where does it show the replay option like it used to? I even tried going to settings but i can't manage to figure this out and it's frustrting.

I'm not sure if this makes a difference but I have the iPhone 4s.

Added (1). Iv'e also googled this but couldn't find much on it, somebody please tell me what's going on or if I'm not doing something I should be?!

Iphone screen is black and won't come back even though it still works?

My iphone dropped and the screen sort of popped up in the front and i tried pushing it back in but then the phone turned black and it still works because i can still hear it and i tried taking it to apple and they replaced the display and the screen is still black! If anyone has a suggestion on what i should do i would really appreciate it or even a way i can get a cheap thing i can use to try to save all my data because i can't plug it into itunes and use icloud because my phone always asks for me to trust the computer and i currently can't do that because the screen is black if anyone knows what i should do it would be much appreciated!

Can I put an unactivated sim card in my iPhone 5s?

I have this refurbished iPhone 5s and I need a sim card to get past the first process when you turn it on. Does the sim card have to be activated? I just want to use it like an iPod but I have an unactivated metro sim card. Can I put that in there to get past the home screen and then take it out?