Yoma 38 Going to Mitzrayim?

Nikinor went to get the doors for the azarah from Alexandria, Egypt. The Ritva asks that there is a prohibition in the Torah to go back to Mitzrayim? He answers that this applies only if his intent is to dwell there, but for businees it will be permitted. He proceeds to ask on the Rambam and others who lived in Mitzrayim on a permanent basis? The Rishonim give different answers on this question. Some say that the cities were destroyed and rebuilt and therefore the issur does not apply. The סמג answers that סנחריב mixed up the world and the people living there are not מצריים and the reason behind the prohibition is not to emulate the Egyptians actions. Reb Eliexer MiMitz answers that the issur is only if one goes back to Mitzrayim in the same way Bnei yisroel left there. (That could explain how the passuk in the תוכחה says that Hashem will take us back there on ships, for that is not the way we left.) The Ritva concludes that the prohibition is only when Klal Yisroel are all living in Eretz Yisroel, however now that there is a decree of exile, all lands are equal. The גבורת ארי seems to hold that it is אסור even nowadays. The חידא says that there is a מקור to what the Ritva says from the Arizal. It is brought down in some seforim that the Rambam used to sign his name "I am Moshe the son of Maimon who is transgressing three aveiros every day." Obviously, he held that under the conditions, he was compelled to stay.