I would be interested in SA and other longer cruises.
I too am 54, female, world traveller, now enjoying cruises. I like my independence so enjoy doing a lot alone. But doing some things together would be fun. I generally organize my own port tours (for myself and others who want to join to share costs).
When it comes to sharing a cabin I am respectful, tidy, quiet, not a late night person, non smoker - and seek the same in a cabin mate.