You make some good points. The opposite extreme to teaching students proper technique and preparing them for competitions is teaching a dance class on a cruise ship. The instructors will only see the students for a few days--at most. They need to find a way to teach something today that the members of the class can do tonight. If they find it enjoyable, some of the students may want to continue lessons when they get home. And if not, nothing is lost. The main thing (in this situation) is for the students to see that dancing can be fun.

Tell them and they may listen.
Show them and they may understand.
But make each and everyone do it
solo; and they will never forget.

You can teach rumba first.because rumba is the slowiest .beginners could follow easier at the beginning.my English is not ver good .i hop my advice could be benefit to you.hope you can understand my words.good luck to you!