Ein Adam Oser Davar Sheaino Shelo

The sugya in chullin on 41a says that R' Nachman, R' Amram, and R' Yitzchak all hold that a person may not assur something that is not his (ein adam oser davar sheaino shelo). In the sugya there in the beginning it is mechalek that by shutfas (partnership) it is different and one may assur. Finally, the gemara says that even acc. to the one who holds that one may assur a davar sheaino shelo, that's only if it is a goy's, however, by a Jew's property we assume that the person assuring only intends ltziura (to inflict pain or to bother him), and doesn't have real intention to assur.
The question on the sugya is acc. to the end of the sugya, where it concludes with this sevara of l'tziura mechaven, so are we reversing the din by shutfin, and also say l'tziura mechaven there. This issue is subject to a machlokes Rashi and Tosafos. Rashi says by shutfin one may assur, and Tosafos says no, that we rather assume l'tziura mechaven.
In the Rambam in Chovel Umazik 7:6 he brings the halacha of ein adam oser davar sheaino shelo. The Raavad adds in "because l'tziura ka michaven". There is a question in the achronim if the Rambam agrees to this point of the Raavad (that the reason for ein adam oser is because of l'tziura michaven). In Chidushei R' Meir Simcha he contends that the Rambam holds that by shutfin one can assur, and we don't say l'tziura michaven, and the Rambam, in fact, argues with the Raavad. Acc. to this the reason the Rambam holds ain adam oser is not because l'tsiura michaven, but because one in fact doesn't have the halachic ability to assur a davar sheaino shelo. In contrast, by shutfin that koach does exist and the Rambam doesn't hold of l'tziura michaven at all. Finally there is another psak in the Rambam by kilayim that ain adam oser davar sheino shelo. R' Meir Simcha suggests there that there may be a special gezairas hakasuv by kilayim that it is like hekdesh, and just like one can't be makdish a davar sheaino shelo, the same is true by kilayim. (The Chiddushei R' Meir Simcha is found in Chullin 41.)