"To the extent that a long augmented labour ending in a vaginal birth with a baby hauled out with forceps is not seen as 'abnormal""
I think you'll find most people don't categorise a forceps delivery involving syntocinon as a 'normal' birth. Midwives certainly don't.
"yes - respecting a woman's request when she asks for pain relief has to be the default setting in any humane society".
As someone who is an advocate for natural birth of many years standing, who mixes with A LOT of midwives, I have never heard anyone support the view that women should not be listened to and that they should be routinely denied pain relief if it is available and safe to administer.
"And yet these zealous UK MWs are sticking in needles freely at the same time as frowning on epidurals"
Most midwives don't 'frown' on epidurals. All the midwives I know see them as a valuable and important tool for childbirth. They do worry about epidural use becoming routine in childbirth, as it has done in other countries which have obstetric led maternity care. Most midwives have concerns about the use of opioids in labour. I know a good number of midwives who see pethidine as a useless drug, who are happy to communicate this view to their clients. Some hospitals (for example St Thomas's) have stopped offering it to labouring mothers.
"I don't see why a lot of natural birth advocates talk about hormones and interrupting the natural flow while ignoring the fact that women are basically being drugged into artifical 'highs' "
I think you'll find they don't ignore this. They are also VERY concerned about the widespread use of opioids in labour.
"From a mental health pov, not to mention the effect on newborns of opiates, I find that a bit disturbing."
I'm not aware that there is any research flagging up concerns about women's mental health following a childbirth involving sedation with opioids, which you'd expect there to be if there was anything to worry about in relation to this given that they've been used in birth for centuries. All 'natural birth' advocates I know worry about the impact of pethidine on newborns.
Point being made: it is false to assume that midwives are generally 'anti epidural' and 'pro pethidine'. They value epidurals for women who can't cope with labour pain, and for complicated labours; most midwives do have concerns about the use of pethidine.