Yes. He has r*ped Medusa on the floor of a temple to Athena, as well as Caeneus who he then turned into a male warrior as a request from her.

Zeus has not.

Achilles, Actaeon, Ajax, Aristaeus, Asclepius, Caeneus, Heracles, Jason and Oileus of the Argonauts, Medus, Perseus and Theseus are a few of Chiron's notable students.

In Greek mythology, Poseidon is associated with acts of violence and misconduct, such as causing storms, flooding lands, and seducing or punishing mortals. He famously participated in the competition that led to the Trojan War by supporting the Greeks after being offended by the Trojans. Overall, his actions often reflect his temperament as a powerful and sometimes vengeful deity.

Yes, on numerous occasions as all the Greek gods were wont to do. He cheated on her with Tyro, Alope, Amymone, Caeneus, Cleito, Demeter, Medusa, Thoosa and Iphimedia, to name a few more known ones.