You can definitely move him to a larger enclosure if you want, however bigger enclosures can make it difficult for young chameleons to find enough food. Cup feeding will allow you to ensure your chameleon is getting all his food, and also enjoy the benefits of a larger cage.
Yeah, I'd say move him to the bigger enclosure and cup feed as well. He may get a little testy for a few weeks to adjust, offering him food by hand makes all the difference.. Even with the most unsocial of veileds!
Just give him time. Also I wouldn't leave the crickets in all day. Put them in for about an hour and then leave him alone. If he doesn't eat then take them out. You could even wait a day in between to get him a little more appreciative!