Confirmation: Is my iPhone Officially Dead?

So I've been having problems with my new iPhone left and right with things like a faulty battery, and constant crashes. I at least wanted to fix the battery problem so I bought a new battery and went about replacing it. From there... the story basically goes the way you expected it to.

I watched an iPhone 5 video not a 5s by accident, so the moment I opened that lid the home button wire came straight off (the iPhone 5 video showed that the 5 didn't have a home button wire and the guy just went about taking apart the phone T_T)

After spending a lifetime trying to change the sticky battery with insufficient tools, I managed to put everything back in place (including the screen... now without the home button function >.>), I tried turning it on... it wouldn't turn on.

After accepting the cruel reality, I decided to reopen the phone. To my surprise (and horror), the screen was no longer stuck at a 90 degree angle... with everything in tact, it's able to bend all the way 180...

Then I also noticed that the silver rectangular box on the very upper right of the phone was loose, and also a piece of black cloth rubber thingy is looking ripped and dangling.

Now the upper right part of the iPhone, specifically the rectangle with the QR code on it, is overheating. No, the phone isn't on, I wish it was. The battery is cold, everything else is cold, or normal temperature, but just that (motherboard?) one part is extremely hot.

So my question:

Can I get away with buying a replacement home button or do I have to buy a new iPhone...again.

Summary of all fokked up parts:

1. Overheating black QR rectangle to the upper right when phone is off.

2. Home button wire is whole but detached.

3. Very upper right silver QR rectangular box (camera) is loose

4. Very upper right... a dangling piece of black cloth/rubber thingy.

Thanks in advance.