I agree with your points. I am pretty much of the opinion it's aliens, and I would like to believe FTL is a possibility. FTL or no, i don't know how to figure out the alien's (aliens'?) agenda. The why and how parts are very strange and too difficult to sort without a great deal more info. Some of the theorist scare me.

I went with no FTL because I get a bit annoyed that interstellar travel is dismissed, when we clearly have theories to suggest otherwise. And, I was really enamored with Sagan's theory of looking for artifacts in the past to find evidence of aliens.

thank you for reading.