only my personal observation -
China doesn't support Iran's nuke program. China wants Iran to comply with resolutions through diplomacy rather than 'sanctions'.
Embargo or sanctions will hurt China economically. However, I feel (personally)
1) it's more about 'principle' that is, sanctions shall not be wielded easily before other means get exhausted. Who will be the next guy to be slapped with 'sanctions'?
2) China shall not give away her 'friends', Iran - for mutual good and regional 'balance' . Who will trust China next time if China kowtows to US?
3) China shall not yield to Obama's blackmail ( currency manipulator and trade protectionism alike). Will US stop all that even if China falls in line with US over Iran??
Israel dare not go ahead for strikes without a resolution.
If 'to keep both sides happy' is impossible China should convince Russia to support and show guts this time
Mostly agreed. Some further observations:
1) Israel has nothing to "pressure" China do anything, though China and Israel have relative good relationship. Both side don't want to poison it.
2) China support Iran's civil nuclear program, but not military program 'cause it against China's interest. It's kinda weird that with bunch of oil Iran wants to develop nuclear energy.
3) Iran's oil count for 12% of China's import, lose this source will certainly cause some difficulty to China, but with central asia pipeline connected to Xinjiang, China can still live with it.
4) Currency appreciation is not against China's interest, China wants to raise the rate against USD, it's just about the right time. And US gov don't won't a trade war with China by slap tax on Chinese goods, because both side will lose heavily.
So, china will keep appeal for more diplomatic efforts, urge Iran to be more clear about its purpose and cooperate with IAEA, if Iran doesn't listen, china probably will vote yes, if Iran cooperate but US still persist the sanction, china probably will veto.