About a year ago I walked into a Chabad house, with no intention to become a Lubavitcher, but to become more observant. Ever since then I got Chabad tefillin a few months a ago and was davening Nusach HaAri until I heard a shiur about family minhagim and how they are more important according to some poskim to follow, in the case of a baal teshuva, than the minhagim that were adopted when becoming religious. A month ago, I switched to a different shul that davens nusach Ashkenaz and have been doing that since, however I still wear Chabad tefillin everyday. Is it halachically allowed for me to switch from Nusach HaAri, if my father, who is not religious except for davening, he davens 3 times a day from an Ashkenazi siddur, to Nusach Ashkenaz? And am I allowed to switch my tefillin to regular Beis Yosef Ashkenaz tefillin?
You may do whichever option you prefer. If you want to keep the nusach Ari you may, and if you prefer switching you may do that also.