Can hobbes’s sovereign ever behave wrongly? if so, what kinds of wrongs might the sovereign commit? why might a critic claim that any moral limits hobbes places on sovereign behavior are at best cold comfort for his/her subjects?

Yes, if he breaks any of the laws of nature, because these are the moral laws for Hobbes.

Violating the laws of nature can be not performing one's valid pacts as a ruler or not seeking peace when others want to do so and also not being grateful.

Moral limits that Hobbes places on the ruler are useless, because when we make a pact with the ruler, we give all of our natural rights away to the sovereign.

We cannot question/revolt because they've our rights.

Can only act if we are in danger ⇒ right to self - defense

there is often only a small difference between what is legal and what is ethical when working with competitive intelligence..

dude you should crop your image so only the question shows. but   can you explain it better