I prefer to think of 'abstract' as 'not spatially extended or localized.'

I prefer to think of it as anything existing at least partly in mind, and then we can say we have an abstraction of an abstraction or that something something is more abstract (something from category theory being a pure abstraction, while something like the category "dog" being less abstract because it connects with a pattern of atoms in reality). By their nature, abstractions are also universals, but things that actually exist like the bee hive in front of me aren't particulars at the concrete level. The specific bee hive in my mind that I'm imagining is a particular, or the "bee hive" that I'm seeing and interpreting into a bee hive in front of me is also a particular, but the bee hive is just a "pattern" of atoms.

Is that a fair summary?

I think that you're stuck in noun-land while I'm in verb-land, but I don't think noun-land is concrete (it's an abstraction).

What's relevant is whether it's useful to have separate concepts of 'the practice of science' vs. 'professional science,' the former being something even laypeople can participate in by adopting certain methodological standards. I think both concepts are useful. You seem to think that only 'professional science' is a useful concept, at least in most cases. Is that a fair summary?

Framing those concepts in terms of usefulness isn't helpful, I think. I'd simply say the laypeople are doing something different unless they're contributing to our body of knowledge. In which case, science as it is requires that those laypeople interact with science as it is (journals and such).

Counterfactuals don't make sense if you think of things as they are?

No, I mean thinking of someone as being scientific doesn't make sense if you think of science as it is because e.g. the sixth grader at the science fair that we all "scientific" isn't interacting with science as it is. We're taking some essential properties we pattern match in science as it is, and then we abstract them, and then we apply them by pattern matching.

I'm suggesting that many of those clustered properties, in particular many of the ones we most care about when we promote and praise things like 'science' and 'naturalism,' can occur in isolated individuals.

We can imagine an immortal human being on another planet replicating everything science has done on Earth thus far. So, yes I think it can occur in isolated individuals, but that's only because the individual has taken on everything that science is and not some like "carefully collecting empirical data, and carefully reasoning about its predictive and transparently ontological significance."

If I'm going to apply an abstraction to what I praise in science to individuals, it's not "being scientific" or "doing science", it's "working with feedback." It's what programmers do, it's what engineers do, it's what mathematicians, it's what scientists do, it's what people that effectively lose weight do, and so on. It's the kernel of thought most conducive to progress in any area.

Maybe we're just not approaching the problem at the same levels. When I ask about what the optimal way is to define our concepts, I'm trying to define them in a way that allows us to consistently ..

I think we are approaching the problem at the same level. I think I have optimally defined the concepts, and I think "behave in a way that predictably makes you better and better at doing good stuff" is what needs to be communicated and not "science: carefully collecting empirical data, and carefully reasoning about its predictive and transparently ontological significance." If we're going to add more content, then we should talk about how to effectively measure self-improvement, how to get solid feedback and so on. With that knowledge, I think a bunch of kids working together could rebuild science from the ground up.

If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis that all things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance... -- Feynman

I'd pass on how important "behave in a way that predictably makes you better and better at doing good stuff" is.