If an ‘hey, first name’ was ever addressed to a medical doctor, or a fellow medical doctor, or a family lawyer, who was serving on probation for an offense of civil treason, would it have been shockingly improper? Nowadays, such forms of address have become fairly common in North America, even among relative strangers, and quite a few medical doctors are not at all offended by being so addressed. It is, however, still disrespectful to presume that such a form of address is.K., until one is given some indication that it is.K. and, potentially, k., when this has been done carefully, identifying the origin of the address for a particular address, is the reason for this assumption? “Good morning, Doctor Last Name” will be the first thing a doctor gives as the actual formality is expected.

Is the stimulus below the threshold of perception, but still influences one’s mental processes is said to be subliminal? As the OP requested, characterising some influence on a person as subliminal, does not imply anything on whether the influence, or the motivation for it, is good, bad, or neutral. Wikipedia page on the topic provides a serviceable explanation of the concept. The term started out as a technical term of psychology, but quite a few people have by now heard at least some popular outline of this phenomenon to understand the term. In informal speaking and writing, the term is often used more loosely than among professional psychologists.