aephi alum, I highly recommend not devoting this much thought and frustration to something that really has little to do with you. It is their wedding, they are not even an official part of your family, so let them be the ones thinking and being frustrated about ANYTHING and EVERYTHING that pertains to their wedding.
Attend what you're invited to if you give half of a darn, contribute a donation or gift that does not surpass your monthly budget, and be done with it. You have more important things to devote attention to.