Can I take an iPhone back to apple for repairs?

I've had my iPhone 4S for just over a year now and for the past 6 months I've been having lots of issues with it.first the sound broke, not a major issue but annoying, then the camera stopped working, it's very slow and now any application I use on it shuts off within a few seconds of me using it.incredibly annoying.
I just want to know if apple can take it in and fix all these issues? And how much it is likely to cost, I'm guessing quite a lot. I'm just sick of having a useless phone.

Get the iPhone 5 or Samsung Galaxy Mega (Note 3)?

I'm trying to decide between the iPhone 5 and the Samsung Galaxy 4 or Samsung Galaxy Mega (Note 3). I know they're totally different operating systems so I'm wondering if anyone has had both and what the pro's and con's are of both. I've had android phones before and an expensive HTC(I know it's android also) but they always froze up on me. I'm gonna be doing a LOT of emailing for business as well as texting and calls. I'm a mom and have a ton of appointments to keep. I'd also like to know what people think of the battery life of both? Any help would be great thanks!

Added (1). A cell phone sales person showed me the mega and told me it was the Note 3.So ok it's not. We'll throw both of those in for consideration.

Applecare and iphone 5 replacement?

I have an iphone 5 which after checking the IMIE nr it appears that i have apple care until next year, Unfortunately I've smashed my screen plus phone hhas few scuffs around edges. My question is with applecare can I get a new replacement Iphone 5 or what are my options? Do I need the receipt etc?

Where can i buy an unlocked iphone 4s?

I want to buy an iphone 4s and i don't where. If you have bought and iphone in a safe place ir website please let me know, n if you've had experiences please tell me. I will appreaciate your answer.

Should I purchase the iPhone 5?

I'm due for an upgrade in a couple days and I'm considering the iPhone 5 in black. I've seen a lot of people having scuffing issues known as "scuffgate" and I want your guys opinion (preferably iPhone 5 owners) and let me know if your having the same problems or if apple has fixed this problem. Do you think it's worth it? Give me your feedback!

Help on Assistive touch on iPhones?

I turned on assistive touch and now I can't unlock my phone it just when I try to slide to unlock it, it doesn't slide so does this happen to other people or just me?