Tanna Island and Mt Yasur

I have read a couple of posts about how great it is to visit the volcano. My question would be is it worth it on a cruise ship stop? Obviously, we wouldn't be able to be there at dusk.

I would also like to hear feedback about climbing the waterfalls and the rapelling down. Looks like a blast on Trip Advisor. The company is called Edge.

Any tips are appreciated. We will be traveling with my parents who are not into snorkling so suggestions about what to do with them would also be appreciated!;)