You're completely right that I'm being sloppy with the language to the point where it's very hard to see what I mean, so I'll do my best to be clear here. By "there are properties" I don't mean there exists some x such that x is a property. I mean that wherever the weak emergence paraphrase for properties is, is true. I tried to signal that earlier, but I wasn't clear.

I think your unwillingness to grant that there are true paraphrases is our area of disagreement here. I think it's unfair to call these paraphrases "weasely words." Why? On the weak emergence picture, "hardness" is still a useful way of describing reality, even if it's not literally true. It would be pretty difficult to have to make reference to structural features every single time you're talking about hardness. So it's fine to say "a diamond is hard" on my view, and you're expressing a true proposition even if the sentence is misleading in the most technical of contexts.

What I'm not really seeing is how this is supposed to "eliminate" meaning. If you say it "eliminates mental content" then I think you have a very strange account of weak emergence. Maybe you can't quantify over mental content. But let's quantify over all the basic particles in the brain. Clearly the relationship between them is producing some effect. That effect allows for things like language. From language comes linguistic meaning. So if you're willing to grant that weak emergence can account for linguistic meaning, I don't see why it can't account for value.

Lastly, would I concede that? No. You'd also need to believe that science describes all there is. If you have those two positions, then I would concede that. But "science describes all there is" is far more controversial than even the weak emergence claim.