Let's be careful with getting rid of tags: We should abolish a tag if it literally serves no purpose, or is actively harmful. As for your specific points:
There's no tag wiki or tag excerpt, making it confusing what it was even intended to be used for in the first place.
This isn't an argument to get rid of any tag, this is an argument to write a tag wiki.
Most of the questions seem to be pop-science-y
Not a reason for deletion either, since nothing about pop science inherently makes a question on- or off-topic at our site.
It seems like if it was an ideal tag it would be more of a 'not-quite-experimental but not-quite-theoretical' physics tag - but of course, that's kind of vague, and most questions on the site could be tagged with it, which is generally a bad sign.
I completely disagree that most questions on the site could be tagged with it. I don't see much "applied" about most of the Newtonian mechanics or quantum mechanics questions we get, for instance. If anything, this tags strikes me as being in the same vein as everyday-life, which I'm not the biggest fan of, but which certainly conceivably tells you something about the subject of the question. Yes, it's a bit "vague", but so is quantum-mechanics when you think about all the different kinds and levels of questions it covers.
Contrasting this with general-physics, which could literally be applied to every question, or physics-careers, which is just plainly off-topic nowadays, I think this tag is at least minimally descriptive of a subset of on-topic questions, and therefore should not be eliminated.