Hi, and welcome to the forum!

Working abroad is both a big adventure and a huge risk, personally and professionally. The ideal situation is to find a large, international employer who will transfer you around to various countries - because that way you're most likely to have all the resources you need (language training, currency exchange protection, etc.). The down side of that is, however, that most employers won't organize your forays overseas to fit in with your life and preferences. If they need him in Thailand when you're 8 months pregnant, he goes and you decide whether you go now to be with him, or go later with the baby, or stay home and wait for him to return.

You should also be aware that almost any "chartered" profession is based on the local laws, and may or may not be directly transferable to another country. That's also the case for your line of work - to be a buyer, for example, in France or elsewhere, you'd have to learn the supplier chains there. It's not impossible, but things do work a little differently everywhere you go and you have to be open to learning about it, and be a quick study. (On the other hand, having overseas experience in things such as buying can really improve your career status back in the UK or wherever you settle!)

Just about any country you go to will require you to speak the local language. It's certainly necessary to deal with customers and suppliers, and even in those "international" companies that claim English as the official company language, the locals socialize in their own language. Plus, you have to deal day to day with merchants, officials and your neighbors in the local language. In France, in particular, there is some real resentment toward Brits who settle in France "and then expect us to speak English for their convenience."
Cheers,
Bev