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I think your temps are a little too high and would try to lower them about 5 degrees. Possibly why he's on the lower branches. How's his drinking ? his skin looks a little chalky looking.
In the first picture of him he looks like he's about to shed, maybe just grumpy ? The Academy has a medical section that has a page on temporal gland infection. Did you just walk into his view when he opened his mouth ?
Here are a few podcasts from the Chameleon Academy that you should find useful ...
Check out "Ep 2: Surprise! Chameleon Babies!! Yay!...Yikes!!" via web:
Check out "Ep 67: Housing Baby Chameleons" via web:
Check out "Chameleons in Baby Cages" via web:
I'm not sure I'm understanding your question correctly but your calcium supplement should be without D3. I like the Reptical without D3 for every feeding and RepashyLoD twice a month. You can buy feeder cups online or make them from large deli cups.
As already mentioned, it sounds like he is just exploring his new surroundings. You have a nice amount of branches but I think I would add some smaller diameter ones that he can grasp easier.