Btw. I had that CTD on the right-click again with my new english campaign.
I had saved it during about 100 turns, but always went to "resume game" after I saved it.
I don't know if that counts as starting a saved game.
Just to let you know.

I play the Supreme Campaign on standard. Some observations:
The other factions develop very slow. Maybe I should go the highest level.
Portugal had turned into rebel faction and was just producing ships. There was already a full stack in front of Portugal with 5 stars plus a new one with six ships when I started noticing. I took Portugal for a few turns and destroyed the shipyard to stop it, but I don't know how far they would go in building fleets otherwise. That's hard to beat: a full 5-star stack.