I think perhaps your comments such as "has anyone got anything positive to say about Qantas?" is a little over-dramatic.
You also need to realise that laying down a challenge like that to an audience such as this, where many support Australia's national flag carrier and have for years, is going to instigate some enthusiastic responses.
I'm sure QF would much rather that they not be in this position and would have preferred that their flagship aircraft not have an engine burst into flames but as many before me have said, I think they have tried to accommodate you as best they can.
I'm also grappling with how this could be "your worst customer experience". Really? On a forum such as FT, making a bold claim like that is a relative statement. If you spend some time exploring the other threads and listening to what people have to say about other airlines, you may just put this experience into perspective.
At the end of the day, I'm sure getting to your son's wedding, safely and on-time is by far your most important consideration, rather than "being like a pretzel". After all, that's what they have alcohol on planes for - to help you calm your nerves