What you're calling caveats are derived from the GR, specifically from asking oneself "Would I like it if this were done to me?". If it fails that test, then whatever action you're taking is not the Golden Rule.
The Golden Rule is a maxim, it does not attempt to spell out concrete actions. It provides a means of testing potential actions by placing yourself in the other persons shoes and asking "Would I like to be treated this way?"
In this sense, it's similar to "What would (Jesus/Buddha/Dad) do?" that others may use as an aid to help determine some moral question. No concrete action is spelled out, just a litmus test for actions one is considering or perhaps as a suggestive guiding question.
The Golden Rule isn't something you can cherry-pick, deciding what you will follow and what you won't. This isn't my caveat, definition, or interpretation: It derives from my following the Golden: "Would I like someone else to decide to follow the Golden Rule for some things but be inconsiderate towards me if they prefer?"
I my answer is "No." yet I skip such things as respect and empathy for the other person, I am not acting according to the Golden Rule. It's possible I may fail to consider it; the rule is no guarantee against genuine error, but if I am aware of it and skip it anyway, then I'm not treating the other person as I would like to be treated i.e. I'm no longer following the Golden Rule.
The Golden Rule does not attempt to place you over the other; it is specifically designed to counter that by asking you to place yourself in the shoes of the other person. ("Would I want this done to me?").
Maybe another way some have of looking at it would be more useful: "Would it matter to me which person I was in the interaction"? If you're treating the other person as well as you'd like to be treated, it should make no difference.
> You can't do to them as they'd like to have done if you don't know them
I should have clarified I was speaking of the Platinum rule. I don't think it's as helpful of a maxim because I think it's less intuitive to ask the question: "How would they like to be treated". It does not provide any reference to anything other than possible preconceived ideas inherent in oneself or one's culture. The Golden Rule references back to me and I can ask myself "Would I like to be treated like this?" I think the The Golden Rule is especially more helpful when trying to overcome cultural or personal bias.
As an example, say I lived in the south in the 1920's. Raised in that culture, I may not be aware of having any ingrained disrespect for "Negroes". I may honestly think I treat them well, especially compared to many others who treat them worse. If I ask the question "How would they like to be treated?" I primarily have my culture and tradition to consider as references to answer that question. Due to intimidation, I don't think asking someone would get me an honest answer. I'd probably continue to blindly conclude that I treat them pretty well. On the other hand, if I ask myself "Would I like to be treated like this?", I think it give me more insight. My reference is now to me, not society, the dominant culture or tradition. It would help make me aware of the implicit racism that I hold within me as part of the dominant culture.