About question 5, is just in case i have problems with my PC and yes if i want to install it on another PC....i'm just a 'crazy' with games sometimes i'm getting bored of the game and need space on hard drive and i could uninstall it.
But if there isn't a limit for reinstall this questions is pointless or if there's a limit if is more than 3-5 is enough

for security purpose to don't keep asking developers for keys