Life is old there, older than the trees...

Excellent catch. Indeed, Scott has said that the planet at the beginning of Prometheus need not have been Earth, but in an early rendition, some scarabs that the Sacrificial Engineer was meant to consume escaped and latched onto a human female, perhaps mutating her in an unintended (but beneficial) way.

I do not think Paradise was the home planet of the Engineers. They are depicted as a species fully capable of planetary scale warfare. Why would they not have weapons on their planet? Why would they not have the capability to defend against one bomber ship? Therefore, either this is an outpost for rebels, or a home for one of their creations. 

As to the Cuneiform you have shown, I think it has no real meaning. Only a handful of people can only read Cuneiform, let alone "write" it. 

Thank you K-Theory. With what we have seen of the Engineer technology capability, the possibilities are endless in regards to the development of their civilization over time and across the universe.

The inhabitants of Paradise were relaxed (weapons down) and this might be because the ship was one of theirs. I also speculated that David 8 could have sent a friendly "trojan horse" type message of good tidings and pleasantries from a distant traveler who belongs to their kind. This could have brought their guard down (but who knows?).

I haven't seen any translation on the black goo bowl writing. It probably says "just drink it and lean forward."