Facebook allows you to display pages by location. You could use this. To manage events, use the events Facebook widget. As to managing several accounts, there aren't any rules per se but there is one clear thing you have to remember: if you have too few and unreliable resources, the more accounts you manage, the more risks you run. Try and keep one account per country and manage it properly. What I have seen happening over the years is companies - like airlines - creating umpteen accounts, then failing and consolidating their accounts. Once they learn how to use them properly then they start ramping up, as their social media budget picks up. Don't think that social media is free. It is people intensive.