Takahashi is notoriously inconsistent and he is even more so at the really big events. He had a commanding lead at NHK and then blew it in the FS. I think Oda is a more consistent, if more immature skater. It's a tossup between them and I think the JF will choose the Olympic skater based on the results of the GPF, Nationals and maybe even 4CC.
I don't see why you favor Buttle and Sandhu if Takahashi goes, but not if Oda goes. Buttle and Sandhu are both inconsistent no matter which Japanese skater they compete against.
Weir has recovered from his ankle injury, but Lysacek is still having problems with his hip. Both skaters are very consistent when in competitive shape, and I think Lysacek can still skate well even if he continues to have pain in his hip, although he has to be conservative with his spins.