That's all true. But even you have "guessed" at things--or as I prefer to call it, applied basic "deductive reasoning", like with your assertion regarding the debit/credit card being used by JDR for the pizza. That was a good example of deductive reasoning.
As long as there is some basis in verifiable facts, and we are being careful to respect the victims, or possible victims, and their families, applying deductive reasoning, and utilizing conditional statements as another tool, seems really all we can do. Ever. In cases like this.
But I do believe it is important to always have some grounding in and reliance on verifiable facts in whatever theory is put forward.
And to keep in mind, NOT EVERY missing person incident, involving young people, is a drug deal gone wrong. This disappearance could be diabolical in nature, or it could be as simple as someone thought JDR gave them a look they didn't like. People have been harmed for much less.