Using brainwaves to give commands isn’t telepathy, any more than winking at someone to send a message. Telepathy is sending and receiving a reasonably accurate data stream between people without any overt signals.
People with some degree of telepathic ability are easy to spot. They consistently finish your sentences when you are talking to them. The further ahead they can project what your sentence is going to be, and the more accurately they select the same words you were going to use, the better their abilities.
Importantly, these abilities can be enhanced by things such as common speech patterns, trite expressions, or if it is obvious where you are leading with your statement. It also helps if the telepath has a good vocabulary, and both whoever is speaking and the telepath are focused on the conversation.
Ummm. Dude. Not to rain on your analysis, but there is predictive software out there that does just that. I've been working with some of it recently. It's uncanny, but it's just good stats and bloated code.
Responses or statements are fairly limited. Rarely do you get a response of "The bus was yellow" when you ask someone what they had for lunch.
/johnny