While I"m sure there are dozens of frameworks to use, it seems as if the Buddhist one fits best here:
- Why are we stuck in a "physical body" in the first place? When I mean physical, I am referring to all the things we "have to" do such as eating, sleeping, etc to keep living in the "physical" world.
- Why are we born into a "separate body" at all?
- If we "had to" be something, why aren't you or I one of those "spiritual guides"?
All of these can be answered by recognizing that you were born into the realm of humans, versus the realm of gods, animals, ghosts or demons due to past karma.
- Are eating/sleeping/getting tired/etc all limiting/disempowering beliefs that we could somehow, within some kinda context/understanding, cast away while still within the physical world?
Yes and no. As long as you have a physical body you are bound by a certain reality, however you can eat and sleep far less and get less tired.
- Assuming you have good explanations to the questions above, the last one is: why did we have to manifest into the "physical" world at all? Things manifest really slowly around here..

Again, because of past karma. This time around, you needed to be whoever you are - but you now have the free will to change and improve your lot.
Stephen
Power-Book Library: Free personal development, success, inspiration and motivational classics