I like the looks of the changes, but still would word the "major deficiency" differently.
Look at it this way: I, as the consumer, am coming to you for help with a specific subject. I already know that I am lacking in the particular area that you are proficient. Personally, I dont want my day starting off thinking that the teacher assumes I have a "major deficiency."
Everyone you may come in contact with will have varying levels of expertise in your structure school. You, as the teacher, should evaluate that person's individual level and proceed as such. Again, some students will not be majorly deficient and will have a decent grasp of the subject matter, only requiring a polishing from you. Others, well let's just say you might have your hands full with a majorly deficient person.
It's like graduating high school and enrolling in college classes such as "I can't believe you don't fluently speak Spanish 101" and "All Freshman are dumb arses"
It just feels negative to me, like I'm being looked down on from the get-go.