about the shakes... how long it takes?? you're right. We don't exactly know how long it will take, and when it will leave you catabolic. Yes fiber and fats will slow absorption, but lets say you're in the gym for an hour or hour and a half, will it cover you that hour and a half of training?
As far as solid foods go, it depends i believe more on the quantity of food also. But usually it's suppossed to leave your stomach in about half an hour. It will go to your small intestine, and large intestine but it will technically be mostly out of your stomach. What you're trying to prevent is too much blood going to stomach for digestion, you want that extra blood going to the muscle. So i think it would be safe to say eating a small steak and potatoe 1 hour before would be ok.