IPhone 5 Shutting down and restarting?

IPhone 5 Shutting down and restarting?

Added (1). My iPhone 5 is less than 2 years old. I replaced the battery in November 2014. Now starting two days ago my iPhone will randomly shut down and restart itself. However the screen glitches before restarting. The phone will not stay normal for more than 3 minutes without restarting itself. There's no water or external damage to the phone whatsoever. I have a apple appointment sunday, will the replace/fix the iPhone with no charge? Also if anyone knows how i could fix this please let me know!

How to get more space on my iPhone? - 2

I have an iPhone 4S and I can't get ANY SPACE. It was originally 8 GB, but now it says that at 5.4 it is full. I can't use it for anything. I have tried going to the apple store but they tell me to delete apps, and I have none left and there's nothing to delete anymore except my texts and one app.

Iphone won't let me download apps?

I don't know what to do?! I use my iphone for school and i wanted to get an app earlier and it just told me "unable to download app" halfway through downloading.

Skype makes everything quieter?

When i start a skype call on my iphone 5c, any music or things of the like get reduced far to much. On computer its a simple enough fix, but how do i stop skype from reducing volume of things on my iphone?

Does this mean anything? GUYS?

I was out last night and had bumped into one of my guy friends. He didn't recognize me until he talked to my other friend and she said aw that's such and such…
Anyway me and this guy use to 'hang out' ages back but anyway when he did notice me he was shocked to see me more less happy or surprising because he looked up and down etc. ( we haven't met or spoke in over a year) so he asked questions how have you been lately I did aswell etc, he was also being all funny saying ' aw look who has the big iphone 6' aha that's nothing but was he just being friendly I guess?

Why is my iphone 6 camera fuzzy?

It was all clear a little while ago, then I went outside and was using it (it was sunny and 80 degrees) and now I'm back inside and it's all fuzzy and foggyish. What happened? Can i fix it?