Um, sorry, but that last example is not quite right. For number 5, you are switching the tense incorrectly and you normally wouldn't use that idiom that way.

A better example: You can wait until the cows come home, but I'm not changing my mind!

To fix the example grammatically in (5) above, you would have to say "I waited here until the cows came home, but you just didn't show up." However, I would never use this idiom in that fashion.

There is interesting history of idioms "The blood is thicker than water".

The quote comes from: “The blood of the covenant is thicker than the water of the womb.” This actually means that blood shed in battle bonds soldiers more strongly than simple genetics.

Now we use it like you described.