QDM - good to see you back Doc!
And how do you avoid stalling or spinning? Watch the airspeed. Let's not make this too complicated
The problem being that it is not that simple! The very fact that the originator of the question was asking about the turn from base to final automatically increases the complexity.
Without going through the math, which I believe was promulgated on page one, what airspeed would you like me to watch?
The harder you pull, the higher the stall speed (some "root" square calc required!). If you learn parrot fashion that a Cub stalls at 37mph, you gash it out to 1.3x3.7 = 48 = 50.
So you know that you can safely approach at 50....... you pull too hard, are a bit slow on the rudder and whooooosh, top wing goes over, nose arcs around and suddenly one is spinning.
To reiterate - I intentionally spin virtually everytime I fly, the only ones that catch me out are the ones I don't expect..... sure recovery is almost immediate but it still makes ones heart beat just a tad faster. I aerobat down to 500' agl but avoid flicky things and stall turns below 1200'.
Some part of me thinks that you'really need to be a numb-nuts of epic proportion not to realise that the aircraft was about to stall (buffet, buffet), hell, ball is out, welcome to Spin City!
But it does happen! So maybe less reliance upon numbers and more on the "feel" would be a jolly good thing?
Stik