Too little time imo, didn't get to the last couple of questions. And I think the "in broad daylight question" is too em broad. Could be anything, I tried the sky and europe, then gave up because there were too many possibilities to finish that sentence.
it's a property that isn't shared with other planets, so it can't be the sky or Europe, as all planets are visible in the sky and from anywhere in the world. But this question could be phrased a little better and should include 'in the naked eye', because Jupiter and Saturn can be seen quite easily in broad daylight if you have a telescope and know exactly where to look.
It is possible to see Jupiter with the naked eye in broad daylight as well. It's hard to see and you have to know exactly where to look, but I have seen it. It was a time when the moon, Jupiter, and Venus were very close to each other in the sky.