1) Hmm, Miller tried to reproduce one specific scenario that not longer exists on earth. In weeks or months, without knowing what exactly it was. Earth had millions and millions of years and lots of locations for that same scenario

2) A snapshot if this specific step, to produce more complex molecules, is possible. And it was.

3) Life forms produces lots of stuff. Some produces methane, yes. Have lost the track though for what this is interesting, sorry

Hmm, methane hydrate is in the discussion to have caused one of the mass dyings in the past. Is that what you mean?

There are and were millions and millions of species. So what's so dramatic when we haven't found all pieces yet? It's more a wonder that we found so much fossils until now. We don't really search for a long time.

For the mule example, i wish we could live a bit longer. There will come the time when a donkey and a horse isn't longer able to have childs, i am sure. Mmh, how do you explain that they can even have childs when there are just completely separated species? That should be impossible then.

In the end, i see that we will not find a consent here. We both interprete the facts in totally different ways. Nevertheless interesting discussion