While you could try to boil down the soldier's logic to an algorithm, the key difference you can't resolve is that the soldier has free will, while the robot has no real choice of its own.

Free will is an illusion emerging from our observation of the behaviour of very complex systems, namely our brains. The soldier lacks free will just as much as the robot does - it's just that the robot is far less sophisticated in interpreting and taking action on the kind of input we're speaking of. The human soldier has the advantage of an evolutionarily developed brain structure and lots upon lots of prototypical guidelines for responding to many kinds of situations, not just ones a developer thought would be handy on a battlefield. There's a qualitative difference alright, but it's not due to any arbitrary conception of "free will".

On your first gripe I agree.

Why am I forced to select something before doing most operations? If nothing is selected, surely it's logical I want to do it on the whole image.

You don't need a selection, but you do need an active layer to operate on. Just click on one in the layers tab. Perhaps it's only me being grown with Photoshop, but this seems coherent with the way layers are supposed to work.

What is Photoshop's equivalent to "Alpha to Selection", which I use all the time? (I'm sure it has one but damned if I can find it)

Ctrl+click on a layer.

I'm obviously not trying to refute any of your statements; just trying to be helpful.