Re: protecting the ball while driving in for a lay up?
All of these are solid ideas. My contribution is to simply remind you that if have picked up your dribble, you're free to do whatever you want with the ball in those two strides of variable length. I do not have a set way of handling the ball when slipping into the lane, it's more about making split reactions based off of what will best protect the rock and take me to the rim. Sometimes I'll cuff, or hold like a running back, or even take the ball over my head and through the middle of two defenders attempting to converge.
On a fast break layup, I was always taught not to rock the ball back near my waist after I picked up my dribble (your body's natural movement will make you want to do so). A key is to keep the ball all the way in front of your body to cut down on someone trailing behind and stripping the ball away.