I just had a review board meeting for my thesis, which includes a mixed methods design with focus groups (qualitative portion) and surveys (quantitative portion). The review board mentioned this same dilemma, it seems sometimes that people outside of the field equate quantitative principles with qualitative research. However, it seems like you have a great number of answers listed already here.
I recommend looking up Paul Bolton’s work or Kenneth Miller, they do a lot of work among underserved populations such as refugees. Paul does a lot of work in regards to culturally-valid assessments and is a great researcher.