Applying for Jobs

Big fan of the game, but I have two questions:

1. Does it matter how many time you "Apply" for available jobs? This involves all leagues. What I mean is, are you any more likely to get the job by choosing the apply button multiple times, or once?

2. My second question is, when applying for national teams, do you have to be the same nationality as the team? This might seem like a stupid question but I ask because not every nationality has an available national team - as far as I know. And I picked a nationality which doesn't have a team or any leagues... Well, the country does have a national team but only grey players and no option to apply for the manager of it.