I think, but I'm not sure, that you're overstating the complication. Looking at your four steps: 1. Everyone should have two credit cards. You don't want a single point of failure (mistaken fraud freeze, for example.) 2. You only check every day, not every transaction. 3. Again, I argue you should have two (Visa + Mastercard) 4. Again. You're just trying to make things sound hard by repeating the same thing.

So. Have two cards. Make sure they autopay themselves. The only new work is checking the exchange rates once a day.