Regardless of music being an art or a craft, or both, it is often true that highly skilled performers cannot teach what they play, and that highly trained teachers cannot play what they teach. However, the greatest performers alive today (for the most part) sit on faculties at big music schools. I'm not talking about currently active pianists, but the old masters that still live today (Graffman, Lipkin, Fleisher, Watts etc.) that sit on faculties at major music schools. Thus, overtime, these great performers become equally skilled in their pedagogical work.
Having studied with Fleisher, it is true that his teachings can injure a student. However, there is a reason why these masters only accept students that already have a solid technical foundation. Thus, physical barriers have no place in this level of instruction; only tone production, phrasing, voicing, and overall structure are discussed. At this level, piano playing becomes a craft of the ear more than of the fingers and hands.
So, these great performers who have become great professors teach both art and craft. At a level where physical technique is still being developed, the only danger is knowing too little of how the human body works to create the most efficient apparatus possible. Damaging a youthful pianist's physical ability is almost more detrimental than not developing one's musical instincts. Thus, it would be wise for you to wait some years to teach.
If you already feel the passion to share your abilities, this passion will only grow with you. Your desire to share more of your knowledge will grow as your own ability to physically play, AND YOUR ABILITY TO HEAR become more refined and acute.
GOOD LUCK!!
AG