How many supernova explode every year?

The whole things seems like such a massive living system that I cannot help guessing that what we think of as universe is just a somewhat large single creature.

It's an appealing idea, but surely there'd be insurmountable problems with the distance/time involved for any part to communicate to another part? It'd be like trying to run a computer with a clock that takes millions (billions?) of years to make a single tick. I just don't see that it's at all feasible and that's without even trying to guess as to how different parts can change behaviour depending on its environment (one commonly used requirement of "life").

What’s wrong with it taking a billion of our years to tick? Just because we, smaller than microscopic beings compared to the size of the larger structures we observe, find it to be a vastly long time, doesn’t mean that it’s a long time for something the size of the observable universe.

For a single bacteria cell, our timeframes must seem immense too.

I’m not saying it’s particularly likely, but it’s a trap to think that just because you can’t fathom the scales that makes it impossible. The universe is huge and very very old. It can afford to wait what is a long time to us for something to happen.

I do think you’re likely right in practice though, and that it is too long for the universe to be an organism. But who knows. We already know that mathematically speaking the heat death of the universe looks identical to a very zoomed in big bang, maybe we just need to zoom out a few billion orders of magnitude to see the big picture, where the vast distances and time scales we see appear as little more than micrometers and microseconds apart…

The problem with zooming out is that the speed of light sets a specific size/time scale so the more zoomed out you get, the more disconnected the big picture is. The observable universe is a mere 93 billion light-years across, so there's a limit on how far it makes sense to talk about zooming out. Also, with the universe expanding, the observable size will reduce over a long time period.

The scales involved are vastly different than the minor difference in scales between bacteria and us - we don't have to worry about the speed of light for anything that we currently consider alive.