I think the bit that's throwing me is the jump from "we know that consciousness exists" to "therefore the universe as a whole must be is conscious" but I bet I'm misinterpreting this somewhat.
Let's take for granted first that you're convinced of your own consciousness. You're more confident in it you say, though not thoroughly convinced, so let's start there. So in light of the fact that you are not simply a being inside the universe, but an integral, inseparable part of it, is you observing the universe not the universe observing itself? This might not be "the entire universe in totality is a big, pondering mind" but it at least means, again given that you are conscious, that the universe is at least as conscious and aware as you are.
If you're not conscious then there's no starting point from which to even begin this line of inquiry.
There's of course also a variant of Pascal's wager in here, except that this one is logically sound, in my view: If there is free will, why not make use of it? And if there isn't, my beliefs aren't my choice anyway.
And just like from Pascal's wager, we can't derive any actual information about the nature of the universe and our conscious existence in it from that line of reasoning.
Also, your doubt in your own free will isn't free, it has a cost. Is that doubt serving you in some way to offset that?
I also don’t think “it’s quite plausible that there is free will but I’m agnostic about it” is a particularly harmful position to have.
Do tell. I also have strong views about free will, but opposing views are worth more than an offhand dismissal.
Personally, I find it impossible to choose to believe something, all things equal, just because I like the implications. The doubt will always be in the back of my mind, "But what if it's not really true?"
I hold to compatabilism. As far as I can tell, the universe unfolds according to natural laws, and we're no exceptions. But we have agency over our own lives, the decisions we will make matter, and we're free in every way that's meaningful.
Do we know this?