Based on the advice here, I'm going to at least start in Singapore, now I just have a problem booking the tickets.
My mother bought her tickets, and I can easily change her second leg to end in SIN for just the $150. No problem.
I, however, am in a bit more of a pickle. I used united miles to book a star alliance reward (flew in on singapore, flying out on united). I'm pretty sure there's no way for me to change the second half now, but do I have any good options? Booking a round trip BKK-SIN ticket in time to make my BKK-NRT-SFO flight loses me a day in SIN, and I'd be quite bummed about that.
Am I in the right forum for this part of the question?
Is there any loophole in united policies that would somehow let me change my origin from BKK to SIN on award travel that had already started?
Is there any way to fly SIN-NRT and catch the NRT-SFO flight?
What would happen (in terms of a refund of points?) if I just booked a brand new ticket from SIN-SFO and didn't board the United flight from BKK-NRT-SFO?
Is there a 2P line? If so, could someone PM me the number?
I know that's a lot of questions, but thank you for your help. :-)