it does from experience....
No
get a new laptop
Laptop batteries generally have a lifespan of 3-4 years depending on usage.
the computer will shut off entirely
Not unless it is plugged into a wall outlet.
The battery is dead.
Either a dead battery - or a faulty power supply.
Yes, you can. Most laptop will work fine without its battery, some of them will not. Dell is usually of those which do not have such problems.
This should not damage the laptop at all, they are designed to be turned on at any time. (Unless of course the battery is dead.)
Yes, a dead battery can break the circuit. A dead battery cannot provide the necessary voltage to power the circuit and keep it running, which will result in the circuit not functioning properly or at all.
Anything that is on and uses electricity. You may also have a dead cell in the battery which will drain the battery.
No, It is not recommended to charge the laptop battery yourself. Laptop batteries require specific charging circuits and power sources. Attempting to charge it manually can be dangerous and may damage the battery or the laptop. Always use the manufacturer's recommended charger and follow their instructions for proper charging.