Unless there is a significant rain problem, rains every day like we are getting here in S. FL, I root my cuttings in black nursery pots sitting on concrete, and the media is 100% perlite. Lots of media probably work fine. It's just the way I do it. If you have rain issues, where the media simply can't dry out a bit, move the pots to a sheltered area, still warm and still getting lots of bright light.
I wouldn't worry about the tiny leaves turning black and falling off. Just something that I see often. Personally, I don't like the looks (color) of that mid-stem cutting. I wonder if it is viable. Mid-stems can be tricky, even for those who root a lot of cuttings.
