With veiled chameleons you can sex them right out of the egg. If it is male, there will be a small spur on the back of each of his back feet. If you're not sure, or want a second opinion, post a pic of the back of his feet.
It's hard to say. Sometimes, they just get parasites from a feeder or a dirty spot in their cage and it's really nobody's fault, so that's why a few poop tests a year are recommended
Just to add to that, I think it is possible that he has a sinus/mouth infection, possibly because of the reasons Jann mentioned, but also I think your humidity might be too high too consistently. If you can lower the ambient humidity in the room, and mist him a few more times a day, then you...
She does have some sinus/mouth infection going on. The vet may have to drain the pus. As for your husbandry, the egg laying difficulty (if there really is any) could be related to your lack of proper supplementation. She needs: Calcium without D3 everyday, calcium WITH d3 twice a month, and...
Hey, I added a response to the previous thread. Didn't realize you had started another. Check that out, and also, it is definitely worth going to the vet. How good is she about being handled? She doesn't necessarily have to go in the box, you could have her perch on your shoulder or something.
I've never seen just the back legs go dark...and the fecal matter hanging is worrying. It is possible that she has impaction, or something large stuck up there that is painful, and that could be causing both the darkness of her hind legs and the disuse. I would definitely take her to the vet...
I'm glad to hear she is doing better. I would still make the changes I mentioned as well. To catch falling water, I use a big plastic tub, so no rust. If you must use a substrate, use coconut husk/coir bedding and you probably won't need the fan after that. Also, did the vet run a fecal to check...
It sounds like there's a bit of ruling out that needs to be done. Can you fill this out:
https://www.chameleonforums.com/how-ask-help-66/
Some possible issues could be--parasite, eggbinding, MBD, husbandry issues, etc. We need some more information to give more specific advice, but a vet...