Do you think people would want to attend a course of that type?
IMHO I think the short answer is no
I personally think you will run the danger of turning people off by using the technical terms in the way you have described
I am putting together my own syllabus for teaching songwriting and although I completely agree with you about the importance of theory and the technical terms you describe - I am trying really hard not to use them to ensure the course is taught in absolute plain English - and the "jargon" only gets introduced AFETR the topic has been taught
I fear you may be going down the "school" route of teaching music, which can turn off more people than it engages
I would take a step backwards and carefully consider your audience and really think about what they want/need to know to get creating - if they are youngsters that want to record pop/rock music you may need to take a different approach to teaching someone that wants to write classical pieces
You may want to consider narrowing down your course objectives - e.g. A pop writer/producer will be interested in "hooks" (which could be a course on its own!!)
e.g. My own course is going to be along the lines of "music theory and production for songwriting", which will teach a combination of music theory, lyric writing and production techniques to produce "radio ready" songs for people to release themselves or pitch to publishers/artists - my USP is that the songwriting theory will be taught "hand in hand" with production techniques that can be used to "show case" and enhance the song
What is your unique approach?
I think you can (and should) use terms like TONIC, DOMINNT, SUB-DOMINANT etc. but the interesting bit is HOW and WHY they are used and how they can be practically applied in songwriting - rather than what they are called - there is little value in knowing terms like "DOMINANT" without knowing how to apply DOMIMANT chords to your own songwriting
From my experience deciding on "how" to best teach this stuff to meet your course objectives is harder than putting the course together - assuming you already have your course objectives set?
Perhaps a starting point would be to write a single "sexy" paragraph outlining and advertising your course so we can get a feel for your objectives