On a personal level, I agree with you about the versatility of techniques and such, as well as the usefulness of HKD hoshinsul in practical applications. The question is whether or not a TKD instructor can integrate those techniques into the class in a meaningful way and truly add value for his or her students. There are plenty of useful techniques for ending a fight in taekwondo as it is.
Generally, regardless of the art, I find that a student is much better served with flawless basics and endless repetition of the basics of their art. I generally disagree that one needs to have every hole filled and a technique for every scenario. I think that applying a limited set of techniques in a variety of circumstances is much more beneficial. If the student has too many techniques to learn and practice, he or she will not have the proficiency in enough of them to use them practically for self defense.
This is one of the few areas where I subscribe to a less is more philosophy.
Most people training in a martial art for self defense are generally trying to prepare for some nebulous "street" encounter with an assailant. They need to be able to use what they know quickly and effectively and in the time that most people spend between white and black belt (average of two years in many TKD schools, three to four in others) there is not enough time to become truly proficient to the point that techniques are second nature unless the skill set is limited.
Regarding the drunk uncle:
I have seen the drunk uncle scenario in more than one place. Uncle can also be substituted with party goer, drunk patron at a bar, etc. Here is my thought on that:
This is not a question of training to handle the drunk once he or she gets out of hand. The best way to deal with this is to be aware of the situation and to extricate yourself from it before it gets out of hand.
If you are at someone else's place and a person or persons are having too much, exit. If the drunk is in my home, well, I generally cut people off before they get drunk, or serve no alcohol at all, so in all likelihood, he showed up drunk, in which case he is being sent home. If he drove on his own, cops are being called.
I don't get into situations of dealing with drunken revelers because I stay away from places where drunken revelers are usually found. I do not patronize bars and clubs. Staying away from such establishments and controlling the flow of alcohol in your own home when guest are over are far more effective than having drunk-friendly techniques.
Daniel