I'll answer that for David regarding the last question.
Our straight Capital One Master Card gives us 1.25% cashback (which we can take as statement credit anytime we want without having to reach an arbitrary amount, and without having to get a check in the mail). And, the currency exchange goes at the Interbank rate, without the .8% or so fee that is imposed by the Cirrus network when we use our Cap One ATM card from our bank account to draw cash.
So as long as we are in situations where we are comfortable using the card and not worrying about security, i.e. similar to the US, and there is no advantage to using cash (such as lodging that charges less for cash), we will use the card. For example, last two summers in London and Canada we charged almost everything, save lodging. Prior two summers in Central Europe we did not touch the credit card abroad.
Makes too much financial sense. The combined rewards, trivial on the surface, add up.