In my experience, when someone is rushing at you, you tend to move faster. Just because Fut Sao moves at a measured pace in the form doesn't mean he moves slowly in application. I have learned the hard way that assumptions based on appearance can be misleading.
Maybe not, but I still say you will fight the way you practice. Does this mean we should really hit and give each other black eyes and less teeth every class? No, but there are ways to still practice your punches right without doing that: wall bags so you can hit full force...making sure you enter deep enough where you COULD actually hit...proper release of energy, etc. But you won't even have to worry about hitting hard if your structure is bad.