If I want to show the truth in my image, then I do very little editing or keep it to what you mention above.

But sometimes, I let my creativity flow and experiment with different colors and changing hues, etc.

It usually depends on the photo and the atmosphere or mood I want to convey in that image. In the end my goal is get that mood across to the viewer, so whatever editing techniques I feel it requires to get there will be taken.

Another instance when I do a lot of editing is when a photo just falls short of where I want it to be. If it has potential, I'll try to make up for what it is lacking in post processing.

See my website for examples and you'll see some very edited images, and other that are natural.

I'd say my rules are the same as yours, although I tend to avoid shadows/highlights as it feels more artificial than the others.

I too tend to avoid it, and for the same reasons. When I do use it it's usually pretty subtle. I may have to experiment with the brush tools added with the new plugin, though - localized shadows/highlights tools might quell the desire I have for some basic masking.