re: Just pondering....
All DNA on earth is so similar it is clear it all comes from the same primoridial organism, molecular genetics teaches us there is only one genetic line, and every living thing on Earth today has the same ancestor. There may have been at some time in the past competing genetic lines, and perhaps some or maybe even all of them arose on other worlds, but it appears competition left only one critter, and it is the mother of us all.
As for your other questions, there are no answers. In fact, some of them may not even be valid questions.