The combination of hair loss, flaky skin and changes in hair texture sounds like something worth getting properly checked rather than assuming it’s genetic. Hopefully the dermatologist can identify the cause. I’d take the photos and your recent test results along to the appointment.
Over-brushing can cause breakage and irritation, but it’s unlikely to cause permanent hair loss in the same way as male pattern baldness. I’d try to reduce the brushing gradually and be gentle with your hair. If the shedding continues, it may be worth getting it checked.
Good to know it’s possible for some people. I think the donor area and number of grafts are the main things to consider rather than just avoiding a shave. A consultation with a reputable clinic would be the best way to know if it’s suitable.
If you still have some eyebrow hair, I’d probably lean towards subtle microblading for enhancing the shape. A transplant can look very natural when done well, but it’s more involved and the transplanted hairs need regular trimming. A good specialist should be able to advise which would suit you...