Some countries have no real comparative advantage do they have anything to trade?
Some countries have natural comparative advantages, e.g. oil wealth or wine making - others don't have these resources or simply aren't as good at manufacturing or the service industry - do they still have anything to trade that other countries would want and if not how to they resolve this?
what was missing from the C.A. video was the impact of free movement of capital. C.A. works only if capital is tied down to a country, as i understand it. If it can flow out (?always to the country with the absolute advantage) all the innovation and wealth accumulates in one place. If that's not right then I need a video to explain it to me.
This was answered in the comparative advantage video. Even if everyone else around you is better at everything, it still benefits you to do what those around you are least good at. That way those around you can focus on what they're best at instead of what they're not as good at. (What they're not as good at still needs to get done!) And that will benefit all parties in trade.