Ruby Jewel
Hello. It can be argued that use of tarot is unethical regardless of the questions presented to the cards/spirits.
Also, if the question only involves the querent instead of a second party or even a third party it can still be "snooping" unless someone is asking for advice. Even when the querent is seeking advice on the best course of action it can be argued that seeking the tarot for this answer is unethical. It's life cheating yourself and the people with whom you are involved (in the situation of topic) out of one of life's learning experiences.
IMO ethics has no place in tarot readings. It's like people purchasing stolen goods complaining that the thief is selling the goods at an unreasonable price.
If I had to choose one thing that I consider to be unethical relative to tarot readings that would be the act of not reading reversals. There are cards such as the 5 of coins and 4 of coins amongst others that have completely different meanings when reading them reversed.
I think serving as a conduit between a person and their spiritual guide is a legitimate endeavor that deserves respect. If that is not the way you feel, then why would you read the cards in the first place. Nobody tells you to conduct yourself in an ethical manner. That is your choice. If you wish to ignore ethical considerations altogether, that is also your choice. The tarot, being basically benign as in the High Priestess, responds either way without judgment. Only you have to live with it. Regarding reversals, please be aware that many people who do not "read" reversals per se, nonetheless take both aspects of the card into consideration in a reading. It is all relative.