I absolutely don't touch my eggs when I candle them. I shine through the top and have never had a problem. the less you mess with them the better the hatch rate in my experience.
A chameleons terrarium does not need to be by a window in order to be happy. Also the danger of putting a glass enclosure by a window is the magnifying sunshine can start to over heat the terrarium. Yes there are multiple issues with this setup however some of your information is misleading...
Red or coloured lights are not good. Also coil uvb are not as effective as linear uvb. Veileds require t5ho lighting with 10.0 reptisun or the 12% Arcadia. For the time being if it's nice and warm out take him out in the sun for and hour a day. As said your temperatures are too cold which makes...
Your Chameleon - The species, sex, and age of your chameleon. How long has it been in your care?
Handling - How often do you handle your chameleon?
Feeding - What are you feeding your cham? What amount? What is the schedule? How are you gut-loading your feeders?
Supplements - What brand and type...
Pupate the hornworms into moths, pupate anything you can, like bsfl, or silkworms. Chameleons that have a hard time accepting other food items usually have a hard time turning down flying insects.
I would convince my gentleman to open his mouth by kinda grabbing him my the back of the head/ neck area. I didn't grab him hard he just didn't like being touched around the head so he opened his mouth.