Laptop randomly goes to sleep/hibernates, squeals, etc.

I suppose my laptop is pretty old, only 2-3 years though.
I have an ASUS K52F-BBR5 and honestly, I don't think I've been taking care of it well enough.
First of all, I've been through roughly 7 chargers, and the battery is plainly terrible now, it can't hold more than 5 seconds until it dies. I know I need a new battery, but it is fairly expensive and I don't have the money for it.
These chargers are very cheap, although they could last long depending on the owner.

1) The replacement chargers are very cheap, about $10 max. Should I spend the money to buy an OEM adapter?

2) My current charger is almost broken. I've inferred that the wire inside the insulation has been slightly cut apart. In the wrong position, the charger sends no power to the laptop. The area where it is inserted into the laptop can get very hot at times. It often blinks from plugged in to not charging and I'm wondering if the constant stopping and sending of energy effects my laptop.

3) Once the power changes from plugged in to not charging a lot, the laptop goes to a semi sleep/hibernate. The laptop lights are still blinking, but the screen acts like it went to sleep. I cannot do anything to bring back the screen. Can I find out why this is happening?

4) The right side of my laptop has squealing sounds and I'm guessing it's my hard drive. I only hear the sounds when I am doing things such as starting up my computer or opening a file. It doesn't happen if I'm idling or doing things such as posting this. The central area of my laptop is making a slight but not as loud squeal sound, I am guessing this could be my CPU?

5) My screen bezel has snapped on one side, revealing the metal part that keeps the lid up. It has become hard to move and that caused it to break through the frame. I don't have any tools other than clear tape to fix this, and it's a terrible fix. Can someone tell me how I can fix the metal part that has become hard to move?

I am sorry for anyone who cringed while reading the terrible problems that my laptop has due to my lack of care. I will give more detail if needed.

I would like to comment just one single point.

DO NOT use a lower-than-spec'd power-supply with your portable. It will power on, but will be running in a brown-out condition, causing shortened life due to excessive heat and this heat can cause abrupt shut downs and may even cause hardware issues beyond repair.

Nice to hear that. But, as per my suggestion go for a new charger. It might be little expensive but, it can save your hardware.