I really do not understand the explanation for the use of a mí.  I have read and re-read your 'lesson' and researched the grammar topic of indirect objects or nouns.   I do not have a particular interest or inclination for remembering the names for grammatical structures, but if you gave me enough examples of when to use a mí and when not then I could work it out the rule myself.  I can't see anywhere sufficient examples nor 'practical' tips for supporting understanding of the structures you are trying to teach .  It is also a very small point when you think that language is really designed to communicate meaning from one person/s to another or others.   How have you chosen topics to indicate the levels of proficiency that you allocate people to? Is your basis for selection of topics purely theoretical or is it based on practical usage?   Think about how children learn language.  They start with nouns, move onto verbs and so on.  They do not need to learn grammar in this prescribed academic way.  They learn by usage which is why more examples and a video of explanation would make this a lot more useful.   I hope that adds some more explanation as to why some learners find this approach pedantic in the extreme and very confusing.  I am learning so as to communicate with Spanish speakers in south America not to take a degree in Spanish grammar.   I think this approach has limited use for learners such as myself.  I am a teacher myself of 40 years or more experience and have a degree in English and Linguistics, so one might assume I would find this approach easy to access but I do not.