Commenting on Carly Fiorina's looks was un-Presidential; and saying that Megan Kelly was bleeding from "her wherever" was an unfortunate choice of words. Saying that John McCain was not a war hero was simply not true.
But the central conceit of the Democrats that Trump, because he has a sharp tongue, is as likely to lob a nuclear bomb as an insult, is ludicrous. Does anyone really think that he can't tell the difference?
Contrast Trump's behavior to Hillary's. According to several accounts, Hillary would actually claw at her husband's face, punch him, and throw things at him during her tantrums. When a Secret Service man said good morning to her, she replied, "Fuck off!" This was evidently typical of her behavior toward the law enforcement assigned to guard her.
Which is more indicative of a personality temperamentally unsuited to the Presidency -- hurling insults, or hurling ashtrays?