While I am not one to say do not entice him with human food (I give mine treats-

) it is probably best not to start him on it so early on.
Do you have nutrical handy...this would be much better than giving into the snacky kinds of things to keep his energy up. But haviing said that, I would too would give him something if I had to make sure he was okay.
The chicken broth certainly would not hurt. Just make sure that you do not give too much too soon as it may upset his little tummy. Glad to hear that he seems to be settling in. I would just leave food out for him and make sure that he is drinking and eating but not forcing him. He's had a lot going on and once he feels safe and settled, he'll eat. Congats!