First, are you sure OW is better than the other alliances? OW does not have great service within India, just to the gateway cities and from Europe that's mainly BA. Other questions to ponder before any other advice is do you want to maximize miles or save $$. The USA/UK/Ireland are the most expensive places to start a RTW. Yes, you can add LAS/SAN, but they are considered a waste of a flight coupon. A big drawback to starting in the USA is the 7-day advance purchase requirement and you must be away from the USA for at least 10 days. With more info, better advice.