These are just the rantings of a soul hanging out on the "lunatic fringe" according to todays standards and teachings. But you asked the questions and I will answer them according to my beliefs and research.
a. How was the universe created/what existed before the universe, existence as we know it etc?
This I don't think man will ever know. For right now we can only speculate and even that might not be accurate. It always amazes me how modern scientists, with our puny brain and short existance can claim to know how the universe was created even using mathematics. How arrogant. The fact is no one knows and we will probably never know.
b. Is there a god/s or higher beings etc?
I believe of course there are. How could it be otherwise in this endless universe of ours? Those much more advanced than us by, say, 1,000 to 100,000 or more years would probably be looked upon as gods as they are higher beings in that they have lived longer and have learned not to kill themselves and have abilities far beyond mortal men.
But I have a feeling that higher, more advanced races that have conquered space travel and the vast distances involved, do traverse the universe spreading their seed, so to speak, much in the way I believe we humans were created with the cross breeding of alien DNA with that of the homonid/ape that was on this planet some 450,000 years ago. It is all written in stone for those that want to read it or even dare to believe it. Those writings are older than the bible and I, for one, believe they are not myths, but fact and that someone does not want us to know for some reason. If one reads the bible against these ancient Sumerian tablets, one can easily conclude that the Bible of today is literally taken from these tablets. That is if they have an open mind.
Because of their vast knowledge and the longevity of their lives they seemed as gods to us baby humans. Why they left and why they haven't returned is beyond me. Some say they are the fallen angels spoken of in the Bible and created man against the wishes of their superiors. Thus, they were banished to this planet forever, never to leave again.
Some also add that we, as baby souls of the universe, must pass through this "schoolhouse planet earth" in human form in order to learn right from wrong and that we will continue to be reincarnated until we "get it right". Becoming human is a choice, but the journey is faster some say.
However, I do believe in an all omnipotent being(s) who did create this universe of ours and that we are a part of him/her/it. Some say, "then they why don't he/they interfere and put an end to all the killing and pain on this planet?" Why? Because it is not their job, that's why. If they did, then we would never find our own way and learn, for ourselves, right from wrong, good from evil, etc. This planet is just a waystation and a stopping place along our journey to true enlightenment and "Godhood" imo. Life on this planet is not ment to be happy. It is what you make of it. It is a learning experience in an evil environment. Do we succumb to the 7 deadly sins or do we learn not to? That, I believe, is the reason for being here.
The true God would not, imo, be a jealous god demanding that his creations worship him or face death. A true God would not kill his creations and if a true God thought he made a mistake then he wouldn't be a true God now would he? He would just be a god (small "g") to us newer souls.
c. What happens after death?
IMO the soul separates from the physical body and enters the spiritual plane where we receive a complete life review and experience all the pain and suffering we ever inflicted on others as they felt it. In other words, we get to feel what others felt because of our actions. We also get to experience the joy we have brought to others through our actions and the difference we made with our lives. It is something I am not looking forward to as I have done much bad before I believe what I do now but it something we must go through.
We also get to meet others we have experienced life with like our parents, grandparents, friends, etc. that have passed before us. Then we have the choice, with the guidance of "higher ups" to reincarnate again based on our past actions or to remain in the spiritual plane where progress is slower. In other words, karma in the physical plane. An eye for an eye, a tooth for a tooth. As you sow, so shall you reap. If you murdered someone in a previous life, maybe you, yourself, will be murdered in your next life. But the choice is up to you.
It could all be myth or fact. I don't know. But based on my many years of research into these matters I tend to lean towards what I have read, written, and researched as it makes much more sense to me than the BS religion we are taught today.
As was written in stone some 6,000 years ago in ancient Sumeria, the "gods" fought among themselves, divided this planet among themselves and taught each of their followers that theirs was the true path and way and that the others were wrong, and each sect still seeks to claim it all as their own. They eventually destroyed themselves with nuclear weapons and started this planet anew.
Thus, we have the myriad of religions today still fighting among themselves for supremacy of this planet and us souls are just the pawns in this game. If this were not true then why have "religious wars" been fought since the beginning of time as we know it? The "fallen angels", "blue bloods", or whatever you want to call them, are still fighting among themselves. Our choice is, do we want to believe what "they" are telling us or do we follow what is in our hearts?" Only after death will you know if you made the right choice or not.