Could I say common sense and get away with it?
You could but that would open a whole can of worms as to what is "common sense".
There is also a verse in the bible that says, "Go build an ark of gopher wood." But you don't see me running out to Home Depot.
In the defense of those who believe in the OT but are not building arks God was specifically talking to Noah here.
As to which of the levitical laws we should follow? None, we should follow the laws that our government has set for us (I'll have to look up the chapter/verse in the NT, but in there it says to obey the laws of the land).
But what if someone tries to use Leviticus to establish the "laws of the land"? Shouldn't we first determine which parts to use and which parts to throw away? I think that if we are going to be using Leviticus we need to firmly establish the criteria for determining what is useful. I really thing that common sense isn't going to be sufficient because it is clear that some things which are obvious to me are not obvious to others and vice versa.