I agree that when you wake up, metabolism is slow and blood sugar levels are low. So it probably isn't a good idea to exercise heavily, without first raising blood sugar levels.
And some people do feel ill exercising after they eat, for the same reason that people shouldn't go swimming on a full stomach. The body uses energy digesting the food, and if they start to exercise or get into trouble swimming, they may feel ill or get stomach cramps (in the case of swimming). I agree a light meal or juice (why not veggies/fruit) BTD applicable.

Now you can't compare a car on an empty tank of gas to a person on an empty stomach, why? because a car doesn't bother going into survival mode.

> Your body's best source of energy is fat because it supplies more calories per gram then anything else. So if it's not using it's fat, your body turns to muscle tissue to meet it's needs. Losing muscle mass probably wasn't one of your goals... was it?

Your concept of fat/muscle tissue utilization, IMO, is all wrong. Yes, the body's best source of energy is fat, and the body will use it, if present, when it needs energy, not muscle tissue. The only time the body utilizes muscle tissue for energy is when the supply of fat has depleted. Long distance runners are vulnerable to muscle tissue loss because they tend to burn fat quickly and run out. And anorexic nervosa sufferers, they start losing muscle tissue only after they have used up all their fat. Have you ever seen a fat anorexic sufferer? Do you think their bodies would sacrifice muscle tissue over fat? How long do you think they are going to hold onto this fat? Do you know that heart is muscle and with anorexic sufferers their hearts also shrink, inevitably shutting down.

With your example, storing fat instead of burning it, is like having spare gas (in a jerry can) in the boot of a car out of gas. If you need it, are you gonna use it or hold on to it.