Well, I don't know that I would go so far as to say that sex taints the relationship -- at least, it shouldn't, though I can imagine that if it's where it shouldn't be, it can cause problems. in fact, I know that it causes problems when it gets where it shouldn't be.

Of course, if I'm planning on having a nice-sized family (hell, a family of any size), I'm going to need a good perspective on sex, anyways. It does create a deep emotional bond, which is the cause of a lot of problems if the relationship doesn't survive. It's about as intimate as any two people cane get, which is why I can't understand people who take it as lightly as the American public take it.

But love doesn't have to be romantic, and there's more to us, as people, than the physical. The trouble comes when people don't accept that -- when they degrade sex and make it simply physical. That would taint a relationship, because it degrades the act and it degrades the people. Sex becomes one more way to stimulate yourself, and the person involved is just a means to an end.

And I agree with everything else you say, necessarily.
The little things can make the biggest impact.