Some of these questions relate to Abiogenesis (origin of life) and not Evolution (diversification of life); these are two different fields of science. This doesn't invalidate your questions, I only point it out to make it clear that deficiencies in one area would not impact the other.
Abiogenesis:
How life began from non life is unknown. Further, proving that one particular mechanism was the actual one which happened on Earth may be impossible.
However, "unknown" shouldn't be taken to mean "completely clueless about". Abiogenesis is a young science, and unlike Evolution, there is competition within the field about which hypothesis is the correct one.
You have some misconceptions about Abiogenesis (eg. the first life were not cells, simple or otherwise. Also they did not reproduce sexually). You also allude to spontaneous generation, which hasn't been in a scientific theory since the 1700s. (Ironically, religious abiogenesis does have spontaneous generation, cause by an incantation "Let there be...").
I hope this vid is useful:
YouTube - 3 - The Origin of Life Made Easy
Evolution:
"According to the above link, the mitochondrial trail has only been followed back, what was it? 170, 000 years. So, that is as far as the "evidence" goes."
This is not the case. Markers within the genome have been used to create the phylogenetic tree all the way down (billions of years). The female at 170,000 years is simply the most recent common ancenstor on the female line. It's just a lable. It doesn't mean nothing is known previous to her.