I mean none that could answer the three questions you said you weren’t read up on.
Number two I don't know, but there are biotic and abiotic theories of petroleum. The abiotic theory is not well supported.
You should probably research shale gas formation, but the rocks are porous and contain liquids and gas that build up after millions of years of pressure. I'm very surprised that no geologist you ever met could ever explain the origin of natural gas. Chesapeake Energy even has it on their website: