Well you didn't start making up stuff until your second sentence - good job! The concentration of oxygen in the earths crust is about 47% not 80%.
Source.
Did you really just state that a large amount of oxygen means there is a large amount of oxygen.
What do you mean it must have come from somewhere? No kidding.
That doesn't follow and is not even remotely logical.
Here we go with the self evident. It is only self evident to you and your flawed understanding of geology and apparently science in general. Yes oxygen is the most common elelment in the crust, so what. Iron and nickel is the most common element in the core.:shrug:
Oh good you are making ideas up and making up defintions for terms.
.
Pure unevidence arm waving conjucture with nothing to back it up but your guesses.
Here is a simple one
Here is a discussion on the core.
evidence of a metalic core
oldie but a goodie
Now you do not have to say you haven't seen the evidence. You're welcome!
I suggest you quit trying to pretend you have a clue what you are talking about.