You sound exactly like me hahaha. I totally agree with maximizing the chances of success and that's probably the reason why we have decided to cover all tests. re the Melbourne test, it's abit weird and it sounds like they are trying to put you off doing this test in Australia. from what I understood is that the sample is sent to Spain anyway so I'm not sure why they didnt get the right results. I know that the clinic have such high success rates and they will do evertying to maintain it and that's probably the reason why they offer these different types of tests.
Re PGS, We are doing it as well. I read somewhere that even young women can produce eggs with chromosomal abnormalities so I'm not taking any risks.
Like you I also think that if i'll get a negative then I'll blame myself for not doing all those tests. we are travelling to the other side of the world, we might as well make the most of it.
Hope you'll make your decision soon, it's a really tough and expensive one to make