These are some thoughts I have had about what I think martial arts instructors should stress. And if they're not then this is what students should stress regardless of what they're being taught. These are just my opinions, of course.

-Training, first and foremost, should be about health. Mental/Physical and Spiritual. The need for self defense may only happen 0 to a few times in your entire life but daily "inner demons" (fear, ego, anger, depression, negative thinking, etc) need to be dealt with all of the time. And if you're constantly improving your own level of calmness and patience you will find it's easy to avoid most would be confrontations from escalating to physical violence.

-Relaxation/calmness/patience are the most important things and should never be ignored. If your student is slouching, correct them every time. If they can't even hold their own body up properly they shouldn't be concerned about fighting. If they are acting impatient about anything remind them of the importance of patience. Ultimately, consistent self control is far more important than the ability to physically control others. You should be able to get yelled at or punched in the face and not react in a way that produces an excessive flood of thoughts, because this will automatically create tension in your body. This is a big sign of weakness. Unfortunately, most supposedly calm martial artists are only conditionally calm. Teachers should routinely throw padded objects at their students or sneak up on them from behind to test how they react to these things. One should react in a physically fast, yet mentally calm and alert way. Swearing, yelping, hyperventilating, etc... are clear signs that the student has a lot to work on.

-Before learning any self defense I believe the instructors should first teach students the "state laws" on self defense, thoroughly. Everything from empty handed self defense, to defense against multiple attackers, to the use of weapons.

-Attributes training and general conditioning are more important than techniques. For instance, if a student's hand is weak he will surely break it if he ever was to punch anyone in the face then maybe he should focus on knuckle pushups first. Speed, timing, flexibility, agility, rooting, and even strength and endurance should be trained even in the "internal" martial arts. Endurance is a factor for internal martial artists because if you just had to run from or grapple someone, and you are breathing fast, the fast breathing with make it literally impossible to relax. Being in this paniced state will render you unable able think clearly and your muscles will be tense. The exact opposite of what you want.

-Nutrition is a huge deal. Without proper nutrition you'll fall ill and frequently be more vulnerable. Indigestion, fatigue, diarrhea, sugar/caffeine rushes, and so on, will all affect your body and mind adversely and put you at a major disadvantage.

-Ignoring the philosophical side of martial arts is a big mistake. A lot of martial arts students and even teachers are turned off by anything that seems "spiritual". My theory as to why they're usually turned off by it is either that they think it's some mystical nonsense or something to do with religion or maybe they realize it is very practical and logical but they have this idea that in order to focus on philosophical concepts that they must be this "moral machine!" That they will have to give up all their bad habits right away
(which is impossible) and not be able to do things they enjoy that might be considered "bad", like drinking or having sex. They need to be taught that it's about personal understanding and growth.

-It's up to the individual student to decide what his or her main goals of training are and the instructor must be attentive to this. For instance, say you have a taichi instructor, whose main concern is self defense, and one of his students is studying for physical health benefits. Another student is only in it for mental health benefits. Another student is only in it purely for self-defense. And an another student just wants to improve his golf swing. If the teacher is partial to self-defense and only focuses on self-defense
application then only ONE of those four students is really getting what they want.

Another thing to note is that practicing what you teach is also important than what you teach. Your students will pick up on everything you do. Your actions (or inactions) have a far greater impact on them than what you tell them does. For example, you can give an hour long lecture on patience then upon driving one of your students home, because maybe their car broke down, you're speeding and cursing at all of the bad drivers. Your student will likely lay in bed that night thinking about the lesson on patience you gave and then immediately remember how impatient you were. However, if you were to emanate patience everyday, even if you never even speak of patience, your students will have a greater chance of being more patient themselves. Ultimately, it's easier to emulate those who you look up to than it is to remember everything they told you about how you should act.

On the same token, if you're teaching taichi then you should teach it as a martial art regardless of if a person is in it for health reasons or otherwise. It's sad how taijiquan was considered "the supreme ultimate/most deadly martial art" and now-a-days gets referred to as a "health dance"
or an "old people's art". I'm lucky if I hear someone just say that taichi has a "martial aspect". This to me is like calling "Muay Thai" "Cardio kickboxing" simply because some people went on to teach that for health only.

I believe if people really care about all these things then they will lead a life of less violence and more health and happiness. They will have a maturity that will allow them to responsibly conduct themselves in society and as teachers. Remember, your very presence can teach, heal or threaten others.

It is also true that too many students want to put their teachers on a pedestal instead of learning from them. If you idolize your teacher; don't complain if he or she starts acting like the proverbial false god.

Also, some good practitioners become bad teachers when they realize how much money or how much ego-gratification they can command from the wrong kind of student.

Yeah totally.

I think the main appeal of the movie "the karate kid" to me always has been the relationship of the teacher and student. While it was just a movie and had some certain retardedness to it, mr miyagi was at least down to earth and friendly and cared more about making daniel into a man than making daniel into a fan.