Ladybones stated many things I wanted to say (I agree with your cham being older then 5 and a half months as well).
Just wanted to quickly add a word on supplementing.
Calcium w/o D3 can be done 5-6 times a week
Calcium w/ D3 once every 2 weeks
MultiVitamin once every 2 weeks
I'd get on the supplementing pretty quick since I can see some slight bone curving on his right front arm in the christmas photo and his veil looks a little wonky (Veiled's should have strong and straight veils when properly supplement).
Also, my veiled is 4 months old and he eats up to 30 crickets a day, however as they grow older they will not require so many. So don't be alarmed if your cham is not eating as much, because to me he looks visibly older then 5 and a half months.
Otherwise I think you have a good general idea on how to care for a chameleon and I welcome you to the forums. Keep it up and I'm sure everything will go along smoothly