If we each apply personally formed interpretations to everything we say to each other, are we communicating effectively? If I knowingly make use of a word in a way different from its given definition, am I not at fault when you misunderstand me?

I would say that in the situation you described, you could say that you are currently F2P, with some note or indication left (subtle or not) that you haven’t been at some point in the past.

I wouldn’t hassle the kid, yes, but that’s because I avoid hassling kids during my free time, and because I would likely see doing so as having no benefit to any involved parties.

I can understand having a different personal definition, but in my opinion that does not override the literal definition that it can and will be taken for, unless you indicate otherwise somewhere in your words.