Uterine myomas may cause poor vascularity and thinning of endometrium thus interfering with implantation. A submucous fibroid may also cause atrophy and even ulceration. Rest of the mechanisms mentioned in the question are responsible for subfeility in patients with uterine myoma. Ref: Essentials of Gynaecology by Lakshmi Seshadri, Edition 1, page - 145.