Both of these things seem like the sort of thing that would only be issues depending on the range of our spaceships and possibly our intent for the planet. If we could reach a wide range of systems I can't see us ever having a legitimate reason to choose a planet with life over one an uninhabited one; that goes double if the goal is some kind of mining or resource extraction, because whereas I could see a possibility of the only planet in a system that supports life also being the only one that would be comfortable to settle down on, I can't see it being the only one with mineral wealth, so excuses would be limited for that purpose even if it was the only system we could reach.