i- In FPSC interviews , your academic background/education does not nessecarily matters rather your performance in interview matter a lot.

ii- Similarly, if FPSC advertsed Masters as eligibility condition, it does'nt mean that they will be preferring a candidate with M.Phil degree.

iii- As regards conduction of interview, yes FPSC conducts interviews through a panel, which normaly comprises 2 FPSC Members and 1 representative of that department, which in your case will be P&D.

In light of above, you should work hard for your interview instead of thinking for any other things.

Good luck.

__________________
'Thee woh ik shakhs kay tasawar saay - abb woh ranayee khayal kahaan'