I do not have any skinks but I've been researching them and bearded dragons for about 7-8 months as eventually I would like to get one or the other. I would just get the dog food rather than cat food if you're opposed to introducing live food, he'll probably like that just as much. Blue Buffalo is a great brand with less preservatives, no by products or dyes, etc. I'm sure there are other equally good brands, I'm just not sure which kind. As far as I've read, the effects of taurine are not completely known but it is no longer recommended as a food source. Also, both dog and cat foods can be fattier than necessary for a skink. I reread and misread thinking that you were feeding him canned chicken. Freshly cooked chicken breast isn't bad, just make sure it's thoroughly cooked and don't use it every day or as the bulk of his diet, it doesn't quite have the vitamins he needs.

Here is a great food chart to follow - http://bluetongueskinks.net/foodchart.html

Personally, I would keep him housed alone and start teaching him to eat live food such as dubias and earthworms. I bet you notice a big difference in activity level.