Again, this is not so. For example, I don't consider expressing opinions which are unpopular in your social circles to be virtue signaling, for reasons that should be obvious. I also don't consider expressions which contain significant effort and reasoning to be virtue signaling. To be virtue signaling, it must be popular in your social circle (or the circle you aspire to), and it must be cheap and easy to do.
If you want to argue that I'm being too cynical, go ahead. Hell, I even described my own interpretation as being cynical. And you don't have to agree with me. But at least do me the courtesy of not trying any more straw men. It's a futile effort. There are more productive uses of both our time.
I offered no straw men. I seriously asked your opinion on those three activities. You snipped those questions and pretend they are strawmen, but the highlighted gives us enough to determine your answers anyway.[1]
Standing for the anthem: popular, easy to do, hence virtue signalling
Kneeling for the anthem: unpopular in almost every context, hence not virtue signalling. Maybe virtue signalling if one aspires to be a detested liberal protestor.
Complaining about PC gone wild: Popular in conservative circles, easy to do, hence virtue signalling when done in conservative circles (or aspiring to same). Not virtue signalling when done at UC Berkeley or Evergreen State.
NRA stickers: Again, popular in conservative circles, easy to do, so virtue signalling in Tulsa, not in Cambridge.
If my reasoning is mistaken, do let me know. I'm simply trying to apply the criteria you just gave in an unbiased manner. You needn't accuse me of strawmen, since you left the questions unanswered but provided criteria which seem clear enough.
[1] To be fair, you stated these as necessary conditions, not sufficient conditions. Hence, only the negative results (e.g. kneeling is not virtue signalling) can be stated with confidence.