I don't "hate" Mr T at all. What I do hate is the attitude that people have towards him. It is irrational and sycophantic. No one ever give me any solid evidence that his inventions are actually of any use (except the high voltage generator, which I have made and which is very impressive). The existence of Patents or 'suppressed secrets' are no evidence at all and neither are stories of American farmers experiences - with respect, they could have been persuaded that they had seen anything that Mr T told them they'd seen.
Transformers ("Understanding of"): I did not say that the Tesla design of transformer was conventional. The air core and the tuning are both significant differences between it and a mains transformer. Have you seen the transformer coupling that is used in radio IF strips or have you seen the transformer coupling that is used in Radio transmitters? No iron there, either and usually, a narrow band of operation. You mention specifics of coil design. If you look in radio engineering publications from the last century, you will find all sorts of wrinkles about how to wind the most effective and lossless coils for MF filtering and matching. It's very hard to characterise these structures (or at least it was, before computers were available).
As you haven't provided a drawing (schematic or otherwise) I can't comment on how this 'single wire coupling' operates. If you can't explain what is going on in terms of conventional EM theory then that doesn't mean anything special except that you haven't analysed what is going on. You are surely not trying to say that Maxwell doesn't apply to coils with a 'T' marked on their design.
'Storage of energy in an oscillating Field' is an example of Resonance. Inductive loop communication systems often to use resonance to improve efficiency.
You haven't said how you were measuring the Power in your experiment. It is extremely easy to confuse measured Voltage with Power and it is the bugbear of reliable RF power system appraisal. If those measurements are not bombproof then an apparent 90% could be a much lower real value. What did this efficiency test consist of? How did you ascertain the power that your source was delivering? What sort of separation have you made your system operate over?
This phrase rings alarm bells with me. I reads a bit 'new age' to be included in a serious discussion about an Engineering topic. What is it supposed to mean and how would it be implemented?