Indeed. misconceptions.....
Spin = Stall + Yaw
It does not matter HOW the yaw got there.....Is it possible to spin from coordinated flight in a stall - of course it is - all you need is a wing drop - dont forget air (due to its nature) does not produce an identical symmetrical flow across both wings - it is chaotic across both wings - especially in the stall...
Yes I teach people to not use ailerons - why is explained. Why they can be used in slow flight prior to the stall is covered in ex 10a - if the student doesnt understand that by 10b then 10a wasnt done properly. Using ailerons causes increases in AoA. Therefore it doesnt matter *how* big the deflection is, what matters is the AoA..therefore even a small use of ailerons on some aircraft can cause either a deeper stall - and likely wing drop - thus causing yaw (secondary affect of roll...) or you may be flying an aircraft with adverse aileron yaw - which at slow speeds will lead to larger inputs of rudder...
As for rudders - I teach - rudder to STOP yaw. Not to pick the wing up....
Just my thoughts - albeit a little chaotic
Let us not forget that that the purpose of teaching is not to cover ALL situations on ALL aircraft types. But to equip people with the necessary skills and knowledge they need to safely fly on the wide variety of types.
Each individual should obviously make themselves fully aware of the stall/spin characteristics of the aircraft they actually fly...it is our job as instructors to make sure that they understand that.