I tried to do a bit of thinking (not too much, I haven't got that many neurons, you know...

).
Keeping Beijing and Shanghai on the Wonders seems the way to go to me too. Whether Shanghai should go for the Pyramids, or switched to Oracle is open to discussion.
In this respect, I think it was a good thing not to trade Mysticism to Germany right now.
What about Canton?
The Granary could be pop-rushed in 3 turns. If we started a Settler then, it would come out about 9-10 turns later.
The advantage is that after building the Granary we would get a steady supply of workers / settlers (and I like granaries).
Disadvantages: no border expansion, we would get to the luxuries relatively late, no military units.
The biggest advantage of building the Settler now is that we would have another city that we could dedicate to building units and possibly a worker, while Canton grows back from pop 1 and builds Granary or Temple.
I would go for it, even if I am not too happy with loosing a worker.
In fact, Canton could start on a Temple after the Settler (with a worker in between? I didn't check this). The Temple could be pop-rushed in about 12-13 turns, and if we irrigate the Game in the meantime, we may not even need a Granary (at least in the short term).
It would be important to work the second BG next to Canton, though.
Other thoughts?