Clear as mud. The IDF has admitted that they have no proof that message came from the Marmara, and there are some odd features about the recording.
Wrong. You have misstated what the Israel Defense Force said which was that all of the voices in the transmission were from boats in the flotilla including the man who said
"Go back to Auschwitz!" and the man who said
"we're helping Arabs go against the US, don't forget 9/11."
The complete unedited audio recording of the entire transmission is typical of maritime audio transmissions.
It also clearly shows that the Israel Defense Force was hearing from more than one boat in that flotilla on the same broadcast channel.
Now if your argument stems from your belief that the comments
"Go back to Auschwitz!" and
"we're helping Arabs go against the US, don't forget 9/11"
are less grave, have no bearing in discussions regarding the terrorists' intentions in the flotilla, simply due to those horrid comments being said by someone on one of the other flotilla boats, that is, a boat other than the Mavi Marmara, then I'm afraid you're on your own. There is nothing I can help you with there.