A hymen is never "intact". In fact it shouldn't be. Of course hymens vary in thickness, size of opening, etc - but there should always be an opening.
It is commonplace for a doctor to make sure an infant female has an open hymen. If the opening does not occur a physician may be employed to fix this before school age. Young girls begin to menstruate as early as 9 years old. Blood needs to be able to pass.
So, to say that the hymen is closed before first intercourse is completely false and rather ignorant.
Let's face it. In this day and age young girls use tampons, masturbate, get pelvic exams, etc. The hymen is rather irrelevant. An empowered, modern woman would hopefully be raised aware or her anatomy and be ready for the happenings of first intercourse. I didn't bleed a bit and over half of the young female population won't either.
Times have changed. I would say it's uncommon to be given a prudish upbringing. Sex education and a new generation of parents ready to give their kids "the talk" has increased awareness and empowered young females about their bodies. There is still some work to do but surgically removing hymens is not the answer. In fact, it's down right unnatural.
Of course I speak from an American point of view. Some parts of the rest of the world have much more work to do before women can be sexually liberated.
And I'm sorry - did you say "acceptable guidelines"? What does that mean exactly? Should all Pagans subscribe to the beliefs that would be in these "guidelines"?
I would have to say that I would be completely against any practice like this for my daughter. My opinion is that the only guideline Pagans need is nature. The tearing, rupturing, etc. of the hymen is part of a natural process.
Birth is a bloody process too. Should we find some way to make that more pleasurable? Some women don't lose their hymens completely until they give birth. Should we do something about that too. Come on now.