Yes, it is of course possible in principle (in fact I am using cats as example because Google just did that). The point is that a person can't do anything equivalent to what human visual cortex does in a fraction of a second by using paper and pencil for multiple lifetimes. The morality and the immorality, just like cat recognition, rely on some innate human ability of connecting symbols with reality.

edit: To clarify. To tell which images are cats and which are dogs, you employ some method that is hopelessly impossible for you to write down. To tell what actions are moral or not, humans employ some method that is likewise hopelessly impossible for them to write down. All you can do is write down guidelines, and add some picture examples of cats and dogs. Various rules like utilitarianism are along the lines of "if the eyes have vertical slits, it's a cat" which mis-recognize a lizard as a cat but do not recognize the cat that closed the eyes. (There is also the practical matter of law making, where you want to restrict the diversity of moral judgment to something sane, and thus you use principles like 'if it doesn't harm anyone else it's okay')

Even better, to my mind, is to think about the scenario from the ground up and form my own conclusions, rather than start with some intuitive judgment about someone else's writeup about it and then update that judgment based on things they didn't mention in that writeup.

The point is that the approach is flawed; one should always learn on mistakes. The issue here is in building an argument which is superficially logical - conforms to the structure of something a logical rational person might say - something you might have a logical character in a movie say - but is fundamentally a string of very shaky intuitions which are only correct if nothing outside the argument interferes, rather than solid steps.

It's not clear to me that I correctly understand what you mean here, but given my current understanding, I disagree. All my visual cortex is doing is performing computations on the output of my eyes; if that's seeing, then anything else that performs the same computations can see just as well.

In theory. In practice it takes ridiculous number of operations, and you can't chinese-room vision without slow-down by factor of billions. Decades for single-cat recognition versus fraction of a second, and that's if you got an algorithm for it.