Sometimes it's like fishing: you can put the right bait in the right place but the presentation doesn't excite him. Try offering the worms on the palm of your flat hand, or held between your fingers while you twirl it around a bit.
Completely normal. As others have said, he's just getting more of his body exposed to the warmth of the light. You can look forward to all kinds of weird and adorable things you'll see him doing.
It's normal for some chams to freak out after a move. As long as all is well with the habitat, just let him be for a while. He needs to get comfortable with his new place.
He's beautiful.
He looks healthy to me. It's perfectly normal to see a range of colors. Overall color can be influenced by temperature or mood. When he goes dark it could just be that he's trying to warm up by absorbing more light. With time you'll get to know his colors and postures.
Eh, that's more of a guideline. If your cham is comfortable with people and the interaction isn't stressing him, then by all means encourage his friendliness.
Just remember that they are primitive animals, and even a friendly cham can get spooked. You'll get to know his signals.
He's a beauty! You can try silkworms if he won't go for the dubia. The cham in my pic over there <--- doesn't care for the roaches, either. They can't spit, exactly, but he will let it fall from his mouth after he crunches it to death. Then he looks at me as if to say, "Dude, that was a roach"...
A video of the behavior you're concerned about would be helpful. It's hard to tell if you're describing a problem or not. Chams do some weird things that are totally normal, and they do some other weird things that indicate a problem with the habitat or the animal.
I can't tell if he's old or if a filter was applied to the pics. Either way, a weight drop of a hundred grams in three weeks is cause for concern. Are you sure about both numbers, or did one come from the person you acquired the cham from?
My other question is did the vet rule out parasites...
First thing I would do is look in the resources section and read the care sheet for veiled chameleons.
https://www.chameleonforums.com/care/caresheets/veiled/
As for the white spots, it could be that she's just shedding. They do it frequently when they're little, and it can affect their mood...
They used to make my skin crawl, then I forced myself to hand-feed them to my scaly pal.
I still don't care for them. I know they're clean, I know they don't bite, I know they're not the disease-ridden, filthy pest roaches we all hate and fear. I know all that and I still don't like 'em. They...