I may be relocating to Asia- Borneo to be exact and I'm looking at OW options and would like to advice from OW FT's.

Which of two options offers the best J class to LAX for my trips back to US?
1). Malaysian Air out of KUL?
2). AA out of Shanghai?

I know CX offers a flight out of Hong Kong to LAX and I understand CX has one of the best J but it seems to be double the costs compared to the two options I listed above.

Malaysian Air out of KUL will be my primary carrier for my local Asian vacations. What is the best FF program, AA or Malaysian Air? I would be in this location for about 4 yrs and then relocated to back to Houston. I know AA has an interesting upgrade system for their FF but I don’t know if this would offer much benefit if I’m already flying J for the Shanghai-LAX or not even flying AA at all?

A majority of my travel will be with my family. Can I sign my kids 2yrs, 3yrs and 5yrs up for FF accounts and can they get status with either AA and Malaysia Air?

Finally, any reason I should choose/consider star alliance over OW for all of my business?

I know a lot of questions but appreciate the help.