Sounds like she is eating fine to me. Superworms are high in fat, plus 3 flies a day will probably sustain or even gain weight. The best way to be sure is to use a gram scale and monitor her weight. I weigh my Chameleon every time he poops, this way you don't weigh his stomach and intestine...
Check out this thread on laying bins. Click Here!
there are some tips on the thread about stubborn females. One tip was it may depend on the type of soil and sand mixture your using.
sounds like he may have ate something like a chunk of substrate that is now protruding. Just a guess without pictures, and even then it would be hard to say. I think he need's a good vet.
Some Info on Dracaena
According to the ASPCA website on Dracaena it is toxic.
Toxic Plants shouldn't be used in your enclosure if your Chameleon is a plant eater. Mildly toxic plants can be used depending on the plant.
As for the Fertilizer question, just change the soil to %100 organic soil...
My monsoon has recently crapped out. I had some hot weather and the condensation went into the the top part of the monsoon where the pump and electronics are kept. Due to a poor design there is a seem where the top rests on the tank, which allows condensation into the electronics on hot days...