You clearly stated that you are getting buzzing playing hard rock at full volume. The speakers aren't designed or meant to provide hi fidelity sound at full volume. There is literally not an element of the Air that you have not found an issue with (case, screen, speakers, SSD, etc). You strike many of us as having an issue with thinking your machine should be a museum piece and not the tool that it is meant to be. It is tiring for people who are trying to address peoples real questions and issue to deal with folks who seem to be impossible to satisfy.
And this is a public forum - the mods aren't here to protect you from the opinions of others.