Addendum B:
The Gemara in Megillah 23a, in discussing the number of people called to the Torah on various days, relates the following:
Ya'akov Mina'ah said to Rav Yehudah: The six [called to the Torah] on Yom Kippur are based on what? He replied: The six who stood to the right of Ezra and the six who stood to his left, as it say "The scribe Ezra stood on a wooden platform that had been made for the purpose; and beside him stood Mattithiah, Shema, Anaiah, Uriah, Hilkiah, and Maaseiah on his right hand..." (Nehemiah 8:4).Tosafos (s.v. Ya'akov) struggle with how the Gemara could have quoted Ya'akov Mina'ah - Ya'akov the Apostate. After all, does it not say in Proverbs (10:7) "The name of the wicked will rot"? Tosafos conclude that this man's real name was Ya'akov Metza'ah, and Mina'ah was a scribal error. (In a similar vein, R. Ya'akov Emden suggests that the man's hometown was Mina and that is why he was called Mina'ah.) However, there are problems with this theory, as noted on the margins of the Vilna Talmud.
The Gemara in Avodah Zarah (27a ff.) deals with when one is allowed to use an idolater as a doctor for healing (out of fear that they might kill us if they have the opportunity). On 27b, the Gemara points out that R. Abbahu was healed by Ya'akov Mina'ah. The context of the statement makes it clear that he was an apostate/heretic/idolater. If so, we must ask Tosafos's question: How could the Gemara mention his name? And if it is mentioning his name here, why not in Megillah also?
The Gemara in Hullin (84a) relates the following question and answer:
Ya'akov Mina'ah said to Rava: We hold that a hayah (domesticated animal) is similar to a behemah (wild animal) in regard to the kosher signs [as listed in Deut. 14:6 in regard to a behemah]. So, too, a behemah should be similar to a hayah in regard to covering its blood. He replied to him: On this [or on you] it says "You shall pour it [the blood] out on the ground like water" (Deut. 12:16). Just like water does not need to be covered, so too [a behemah's blood] does not need to be covered.We see Ya'akov Mina'ah quoted again, which raises the same questions as above.
R. Reuven Margoliyos, in his Nitzotzei Or (Megillah, ad loc.), suggests that the Talmud would quote a heretic only in the context of disparaging him or when his identity is halakhically relevant (see also Seder Ya'akov to Avodah Zarah 28a). Thus, in Avodah Zarah it was necessary to note his status and in Hullin, the heretic was cynically questioning the halakhah and was forcefully answered in return.
However, R. Yitzhak Isaac Haver, in his glosses to Hullin, R. Wolf Boskowitz, cited by R. Avraham Shlomo Blum in his Yisa Verakhah to Hullin, and R. Aharon Hyman, in his Toledos Tanna'im Ve-Amora'im (vol. 3 pp. 780-781), implicitly reject R. Margoliyos' reading of the passage in Hullin and revise the text to say Ya'akov Metza'ah, like Tosafos do in Megillah.
The conclusion, though, is that according to Tosafos one may not quote a heretic unless there is a specific benefit in noting his name.