1)
"Point", maybe?
the point that there are different types of insurance
I don't know the exact context, but the example sentence seems to mean いろんな保険があることからすると, i.e., something like "according to the point that there are different types of insurance" to me.
4)
Oh, yes, you're perceptive! It's my mistake. That's not the contraction of 置いていない but the negative of 置いてある, because of the が. If it's 危険物を置いてない, the both interpretations are possible.