1-7 Are uncontroversial, as long as there is a possibility, multiverse hypothesis guaranties that it would happen every once in a while.
Yes, but the issue is that you can't demonstrate the possibility of any of them, thus you cannot describe them as necessarily possible in this way.
1 & 2: These are both a given based on the OP, I've been sure to stress this. I do not actually agree that the universe is fine-tuned or that multiverse explains why, even if it does happen to be fine-tuned. Please understand I am suspending disbelief to participate in the question. It doesn't mean I cannot present an argument to either of these points, it just means I won't be presenting one as a courtesy.
#3 is actually two assumptions in one. First that life is frequent in the multiverse, second that intelligent life is frequent in the multiverse. Life is not frequent in our universe. Intelligent life is not frequent among life. You must assume both of these in order to get to #4.
So, my statement is this:
3a: Life IS NOT frequent in this universe, therefore IS NOT frequent in the multiverse either.
3b: Intelligence (human scale or better) IS NOT frequent in life, therefore IS NOT frequent even in the infrequent life in the multiverse either.
Both of these must be shown to be incorrect with a counter example of observable reality, such as I am showing you.
The only controversial is the last point; sure I cannot prove with certainty that artificial world would outperform natural world, but it seems a reasonable (or at least possible) assumption.
As I said, simulation is probable mathematically. Its not really something I believe, but from the perspective you present I can see how a simulated universe might hold water, given far fewer assumptions than 'artificial actual' universes.
Not to mention that the burden proof would be in the multiverse theorist.
I do not cater to the idea of 'burden of proof'. Its a non-argument.