It's cool man, if you didn't mean to be that harsh then it's all good.
As far as the car battery stuff goes, I talked to my friend who knows a lot about cars. He said that removing the battery cables would not do anything to the car.
Of course it wouldn't do anything to the car. it would fuck up anything stored on the electrical system.
unplugging a battery doesn't DAMAGE anything.
your friend doesn't know what he's talking about, or didnt take into consideration that a car is also a computer. My brothers a mechanic. Think about this: anything electrical on your car with a memory (radio, ECU settings, automatic seat/steering wheel adjustments basically anything with any kind of setting) will be reset unless it has an external power supply (some anti theft / alarm systems). The memory used on cars is not like flash memory. It needs power in order to keep storing the settings.
Newer and high end car stereos have a function that if power is ever lost, they will not function until a secret code is entered. This is so that if the stereo is stolen, it has no worth without the code. So if you pull out the battery, you engage that function of the stereo. (removing the battery / unplugging it) unless they have the reprogram code they won't have any music. Most people don't even know where this paper is. When the battery on my mom's A4 was replaced I had to have the dealership reprogram the radio and reprogram the ECU because the fuel/air mixture ratio was off, causing the car to run poorly and lose power.
While not necessarily BAD for the car, its just a bitch to reprogram anything. And then imagine after she's like "FUCK MY CAR WONT START" and she called her dad and AAA before even going back inside so she doesn't look stupid... I can see that turning out well.
Hot girl: dad my car wont start can you come check it out
dad: wtf i just bought that / wtf / wtf. all responses are going to be a variation of wtf
hot girl: i dunno its not even doing anything. theres no lights.
dad: oh ok your battery is dead i'll come give you a jump
dad arrives, opens hood, sees cable is unplugged
dad kicks your ass for being retarded.
Bad idea to mess with someones car for any reason. Cars are (counter-intuitively) actually very fragile and very expensive.