Well I think I more or less agree with the base level of the argument. I think it makes sense, given what we currently know about the laws of nature and logic, to think an infinite regress of "movers" (by the way, I completely despise that particular term) is impossible. However, I do think it's very probable that our sense of the laws of nature and logic are incomplete and cannot be applied across the entirety of the universe without modification. It is for this reason that I'm putting the "infinite regress is impossible" premise under a "maybe." But I'm leaning more towards it being true than false.

The real problem I, and probably most atheists, have with this argument comes around this part:

The unmoved mover also must be basically personal, for the motion proceeded of itself, being unmoved, and therefore contained the faculty of deliberation, ergo consciousness.

To me, this is pretty much gibberish. I've spent probably about ten to fifteen minutes reading and re-reading this sentence and I honestly have no clue how the jump to "deliberation" is made here. What I genuinely think is happening here is that at this point we're talking about a "being" that exists completely outside of our realm of experience. We have absolutely no way of knowing how such a being would behave. A very natural thing for the human brain to do when it meets a problem it cannot solve is to personify it. You think it makes sense to talk about this "unmoved mover" "deliberating" because it's the only way you can make sense of it. I do not think you are in any way justified in doing this.

But of course, feel free to tell me why my interpretation of what's going on here is wrong. This is honestly getting dangerously close to the most baffling parts of theistic beliefs from my perspective; so if you could explain it to me in a way that makes sense I would incredibly grateful.