I see those many threads saying that sanding is only common on "Fresh Paint".

And people usually don't sand "Factory Paint".

I am really sorry but I am not an expert... doesn't every new car get "Factory Painted" ?

Lets say that my friend bought a car recently and someone made a small scratch, can't I sand hes car ?
I have a paint gauge if that's the problem...

Another question I wanted to ask, is can I hand sand a car without a Polisher ( without a sanding disk ) ?
I have a Flex 3401, And I don't really want to buy another machine right now =/...

I bought all megs sanding papers ( and that black sponge ), 1200, 1500, 2000, 2500, 3000....
Could I just use them all by hand ? and get awesome results ?

And another Pretty important question... How much paint does sanding remove compared to a Compound and Finishing polish ? ( I know that compound + finshing is about 4 Microns removed ? ) Any Estimate ?

Everyday..... learning something new... Love this..