WIY: If a Goy is Assur then a Goy is Assur. An Eved K’naani isn’t a Jew. He doesn’t have Kedushas Yisrael. And yes, Tevi was a Goy and a Talmid Chacham. That doesn’t give him Kedushas Yisrael.
Also, a Sukkah built by a Nochri is Kasher. How does that fit with this? Halachah isn’t about “feelings” or who “belongs” in a Sukkah. Halachah tells us who belongs in a Sukkah. It tells us who is allowed in a Sukkah and who isn’t. If you want to determine that based on who it feels right if they “belong” in there, then Reform Judaism allows you to determine Halachah like that. But last time I checked, in Orthodox Judaism, Halachah tells us how we should feel and not the other way around. Halachah tells us who “belongs” in a Sukkah. Our feelings don’t tell Halachah who “belongs”.