Thanks for outlining some of the ways rabbis dealt with the commandment. Apparently, your ancestors share a trait with some of mine: looking for patterns where no pattern may exist. To be fair, this seems to be a human trait. We're pattern makers and seekers. It's a useful thing, most of the time. The flip side is that it may lead us to erect elaborate constructs where none is needed
"You shall not steal." The best place to start is to take the commandment at face value. Don't take something that belongs to someone else. This is the most intergenerational of commandments, the one most readily understood regardless of one's age.
It's concrete. Don't take Susie's blanket, Mom's wallet, chewing gum from a store shelf. You can see that which tempts you! Others can as well. In fact, all the senses may become involved: sight, taste, touch, smell, hearing. The prohibitions against idolatry, adultery, and even murder require, for most of us, a leap of imagination when first heard. "Don't steal," though can be brought to life with something as simple as a purloined comb.
Our comprehension of the commandmant's range of application ought to expand over time. Stealing another's time, work, rightful place in a relationship, resources or opportunities--the commandment grows as we grow. The commandment casts light on its fellow commandments. For example, idolatry might be considered a form of stealing from God. Murder is the ultimate act of theft against another human being, and so on.
Well...I'm writing on a public computer, and the line of would-be users is long! More later.