Well to be honest, I am not sure exactly what you are asking. I have read and watched many things explaining the theories about the inner structures of the pyramids. I assume this is what you are asking me. What do I think they were trying to achieve or what is the purpose with these designs.
I have a rather boring explanation. Their religion fueled these constructions.
The ancient egyptian religion is based on the idea that you need to be preserved so you can undergo a test after you pass away. You need to be able to recognize your corpse or the beings in the underworld will have power over your "spirit" or "soul". So preserving the body was their goal and the only way to make that happen is to protect the body because people who could afford to do this had to be wealthy to prevent their bodies from being messed with or looted.
They believed that you could take possessions in this life with you into the after life so things you were buried with you could take with you and often times these things were valuable. To prevent robbers you needed a way to prevent them from stealing these items. So passages were built to make it difficult for robbers to find their way to the correct burial chamber.
There is some physics involved in the structures. When you have thousands of tons of lose rock above you, you need to be creative in how you construct rooms inside these structures or else they might cause a collapse. So when you see the kings chamber for example, it is designed in a way to reduce the stress caused by the tons of stone above it. That is why it gets the shape that it does.
The vents that are too small for people to enter has another explanation about their religious ideas that the "Ka" or soul could travel through these tunnels to make it's way out of the pyramid and not get lost. The thing that doesn't make sense is that the person being buried in the pyramid was often times dead for weeks prior to being placed into the tomb. So why would the soul need these passages unless the process takes months to undergo.
To me it is just more religious nonsense and there is nothing mystical about it all. As much as people want to believe there is some kind of magic at work or something cosmic, the reality is, the builders were motivated to design these structures the way in which they did because they desperately believed that they could exist for eternity if they did it successfully.
I'll admit I like some of the concepts of the ancient egyptian religion but it doesn't help the fact that I think it is not actually true. We are humans and we cant' stand the idea that we are given a finite amount of time to exist and desperately cling to ideas that we exist for ever. I think that is impossible and irrational to believe. It just doesn't make sense how it could possibly work.
If you have a soul that exists for ever, what fuels it? Everything we understand about the universe requires energy for it to function. Why would the soul magically be different? Why would it be able to exist eternally without requiring energy when NOTHING else does? I find that hard to accept that a soul would be an exception to this fundamental law.
Not only that but I would HATE to exist for ever. Existence would get boring after a while and there is nothing that I could do to keep myself entertained for that amount of time. I doubt I would want to exist longer than about ten thousand years. I would go crazy with boredom let alone exist for ever.
The after life would have to be drastically different than this existence for it to work where I wouldn't get bored but if it were so different, I would be drastically different as well. Which means why have this existence in this way only to have another existence that is so drastically different? I find all that very hard to accept and I end up being more rational and simple explanation.
Which is, we exist for a short time and die and we never exist again. Some refuse to accept that as being a possibility because it sounds negative and even scary. Because we are attached to our existence and our lives and enjoy being aware of our lives and can't imagine or fathom what it would mean to be non-existent. But the best way to explain it is, before you existed, you weren't aware that you didn't exist, no skin off your back sort of speak. So when you pass away from this life you won't even be aware that you are dead so why worry about it?
Sorry for long explanation and slightly off topic but a long story made longer.