I check the travel section of Bing.com for flights. It is a search engine that comes up with the cheapest prices for flights from any airline. Good luck!

I'd doubt it, but perhaps someone else can answer that for sure.
You'll also want trip cancellation and baggage insurance.

Your particular plan administrator with Blue Cross / Blue Shield will be able to confirm what coverage you have when outside the US, some have 'International' coverage some do not it all depends on which plan your employer or you chose to participate in.