1. As others have pointed out, AS seems to be content working to support anyone but Delta to get traffic to/from US gateways, and giving JX preferential treatment would undermine this position. That having been said, JX could potentially sweeten the deal for its customers by pursuing specific beyond gateway city pairs that Delta (and United) pretty much dominate by eating more of the costs themselves. I could envision Alaska helping them out a bit on this front (i.e better pricing) if it was well executed/targeted if the value proposition specifically included hampering Delta's Seattle buildup (Alaska behaves as a rational economic actor for the most part, but Delta has managed to get under its skin at its home base).

2. CZ's partnerships with OW sans-CZ are quite strong (I.e. much stronger than its previous position in Skyteam, where it happens to still have several toes in the water, including a subsidiary that it code shares with at will). From a passenger standpoint, you usually don't get lounge access or much else in the way of priority services, but you can buy competitively priced tickets to places other than Beijing, Shanghai, or Guangzhou without transiting in Hong Kong. So, AA, BA, JL, QF, etc were able to get much of what CZ brings to the table, while CZ isn't burdened by dues or having to conform with OW guidelines.