Re: Commitment into the attack
I really think this is THE most difficult aspect of ANY martial art. you have to assume away SO much of the reality when training with attacks. A lot gets lost in translation. I was running a class friday using four ounce gloves and teaching my guys how to deal with attacks from the guard (ground and pound). You have to agree to a level of force and the guy getting hit has to realize that the punches are being pulled.
Setting up the boundaries and conditions takes a great deal of experience and IMO it is an "Art" in and of itself to coach attacks and keep the conditions such that it achieves the desired results of the exercise/training.
If you overwhelm a new student with too much before they are mentally and physically ready and have developed some baseline skills to react...then you are really wasting your time.
Conversely if you don't train this at all and put on some good "combat pressure" and make it uncomfortable and ALIVE at some point...your students are never going really learn much IMO.