>>5 No, it is not.
Cracking passwords is not illegal in all countries outside than the US.
In my country, it is only illegal to use someone's WiFi service without their express written permission. Getting their password in the first place is not using any service they are paying for, and therefore is not illegal.
However, I suspect most people are after free WiFi, and not necessarily testing technology, so that would be illegal to use it without their permission.