Andrew, I hope some one posts from Florida that they are having success with semps in your growing conditions.
At this point I think you need to do some experimenting. I would bring some of them indoors at night for a cool down. Semps usually go into semi-dormancy when stress by heat and don't do much growing when stressed. That is opposite of your heat loving tender succulents.
When you repot, try different potting mixes as an experiment. Now is the time to try all methods that make sense in your heat and humidity. The ones that end up thriving will tell you what it is you need to do to be successful in growing them. I look forward to seeing how the experiments turn out. Please keep a photo journal for us, it could help others in your part of the world to grow sempervivum.
To make the experiment really useful I would make sure each cultivar is represented in the different growing conditions. As some may just be better at handling your heat and humidity and some that won't.
Hope I am making sense here?
