IIRC Hawking expressed concerns about that: if we were to be found by a more advanced civilization, then we would in all likelihood be ultimately destroyed, because there seems to be a recurring pattern showing that this is what happens when a higher civilization meets a less advanced one.
I'd be inclined to agree with #11, in that domination is always motivated by resources, and aliens visiting earth would likely already have all the resources they need. I'd hope they are motivated by curiosity more than trying to get hydrocarbons or whatever.