I guess it depends a bit on what Pakistan deem as good relations. Would they view it as betrayal if were to build good relations with India?
No,the only way pakistan would feel betrayed is if our government changes its position on kashmier.
What if China demanded them to do something that goes directly against our interests and threatened them with economic sanctions if they didn't comply?
No chance of that ever happening since pakistan is the only country able to help them against india in case of a war between China and india.