Would appreciate advice on which airline's star alliance program to join:

(1) What is your home airport? (SFO, LAX, MCO, etc.) : LHR
(2) What types of fares do you usually buy ? (C, F, Y, etc.) Fly J for work (approx 20 - 50k per year miles on Star alliance) and Fly Y for personal travel
(3) How many miles do you usually fly each year? (<25K, 25k-50k, >50k)
(4) Do you have any kind of status at present? What is it? (UA Premier, M&M Senator etc) BA Gold, none on Star Alliance
(5) What is most important to you in a FFP? (Frequent upgrades on travel, priority services when flying the airline, good award redemption rates, free lounge access, etc.): Upgrades using miles and good redemption, especially on Air India or other airlines flying into India
(6) Which routes do you fly most often (US Domestic, Transpacific etc) : For redemption on LHR - BOM/DEL
(7) Preferred Airlines: Air India, Singapore
(8) Do you travel for work or pleasure? (Can you chooose your airlines, class of service?): Both - I can choose airline freely for both

Many thanks for your advice and insights folks!