When are you planning to take this ambitious itinerary? I cannot imagine the complexities to come with CV19 restrictions in so many countries. I'm glad you are a Travel Agent, you probably have the knowledge to deal with all the ever changing rules.
I have been researching just a trip to Canada, using some SQ miles, later in the year and have discovered that some provinces, like the Australian States, have different rules for various countries. Prince Edward Island, for instance closed the bridge so even Canadians could not enter for a while. I want to go to Newfoundland but there are differing rules, apparently, if stopping in Montreal on the way.