I'm NOT a piano teacher, so I can say, sometimes some of them can be a bit snobby, about what sort of instrument a pupil has, or what music they want to play!
I played drums for forty years - pubs, clubs, pantomime, stage shows etc. I had played piano 'by ear', also trumpet as a teenager. Later, had a Yamaha organ and used Kenneth Baker books.
When I got in to primary education, as Teaching Assistant, I had recorder groups for ten years, did a Keyboard club with Year 6 (making up own tunes and simple improvisation), and coached Yr2 children on percussion to accompany the Christmas performance each year.
My main aim was to give children a 'taste' of making music, and to have some fun. And these were mostly kids from deprived backgrounds, who otherwise would never have experienced any kind of music making.
If we accept your Grade 8s as evidence you are 'up to the job', the question is how you relate to pupils, particularly younger ones, and how you approach their learning.
I have replied on similar topics several times, so if you Search my name, and keyboard, piano etc, you will see more of mu ideas.
I'll try and come back in a few days, to see how you are getting on.
Good luck.