I have recently moved to a place where the only Orthodox Jewish presence is that of Chabad. My nusach is Ashkenaz (haGR"A) and I always make sure to use my own siddur while davening in a Chabad synagogue. However, since I have a good voice, I have been asked repeatedly to lead the Shabbat services, for which I had to use the Chabad nusach. Since it is a small community, I did not want to offend anyone by refusing the honor. Now I feel that if I refuse it would seem even more offensive, since I have done it many times already, and they love my davening. Is it permissible to act as a shaliach tzibbur using a nusach other than one’s own?

Yes. That is the way one should do. A Shliach Tzibur should daven the Nusach of the Minyan. Rabbi Yitzchak Grinblat