Thank you for your question.
These statements likely would not constitute valid grounds for a defamation action. New York and other states recognize as a defense to defamation actions certain privileges, including the opinion and fair statement privilege. This privilege protects the right of the speaker to make opinion statements. Opinion statements are statements that can't be proven true or false.
It is possible that labeling a person a "hothead" or "troublemaker" implies some type of false underlying facts. In that way, there is potential for an action in defamation.
Additionally, when a plaintiff in a defamation lawsuit is a private figure and the allegedly statements relate to a matter of legitimate public concern, the plaintiff must prove that the speaker acted "in a grossly irresponsible manner without due consideration for the standards of information gathering and dissemination ordinarily followed by responsible parties." Chapadeau v. Utica Observer-Dispatch, 38 N.Y.S.2d 196, 199 (N.Y. 1975). This can be a difficult standard. If the matter is not a matter of public concern, the plaintiff must demonstrate that the speaker spoke negligently.
I hope this information is helpful. Best of luck to you.