#3 is my favourite of the four - I can't help but think of White Mice Overlords carrying out the experiments.

As a non-Christian who doesn't believe in any form of a "God", #2 is how I view religion. There has to be something else life is worthless. Something afterwards to make it worth living. I think I'll call it "God".

You might be interested to know the #4 is an accepted theory to explain that the must be a God. I think it's more commonly known as the "Watchmaker Analogy/Argument" - by way of an analogy (which I'll get to in a moment), the theory argues that design implies a creator. The analogy is that a man is walking through a desert, and he sees a watch lying in the sand. The man looked at the watch, opened it up, so the intricate mechanisms that made it work, and thought that it MUST have a creator, for it couldn't create itself. It translates to organs in that with them being so intricate (such as, you said, the eye or the brain), they MUST have a designer - they can't have eveolved by themselves.

The theory was first put forward by William Paley in 1802, and was only challenged by Darwin's formulation of the theory of natural selection.