I will reply the 2nd part first.
Sex had never been a taboo in Santan Dharma. It was after invasions of fundamentalists of two major Abrahmic religions that women were kept under control, mainly due to fear of them being kidnapped or to copy the invaders. Both Islam and Catholicism are very strict on sex and thus India became a little touchy about sex.
in BC era, there was a festival called Madanotsava in India, where all young boys and girls would go to forests, dance and enjoy and finally came back with their life parterner, selected during the Utsav.
Almost all of our gods have their counterparts (wives) and Krishna leela is full of free relations between boys and girls of those times.
Tantra Philosophy of Hinduism has sex as sacred ritual and there are techniques where one can be enlightened through the sexual union.
Sacred symbol of Linga and Yoni... also has sex ritual though in esoteric form.
Thus sex is an important part of Hinduism and it is not really shunned by Hindu Philosophy. Of course Sex is not freely advocated in Hinduism and we are asked to observe Brahmcharya till we get married.
Sex is only forbidden for Yogis and those who are on higher paths of spirituality, but that still is not strict rule.
Khajuraho Temples are beautiful artifacts and show the richness of Indian culture at the time when Tantra was accepted openly.
the temples have sexual images all around the temple and there is no such image in the inner "Garbh Griha"...it has a clear message
Those who still have sex in their mind, will continue revolving round the temple, and those have gone beyond sex, will enter the temple and will continue his journey of truth there.
GREAT APE : I never wished such question and answers are discussed on a board where trolls of other religions are ready to insult our faith on such flimsy grounds. Still now since this Q has come on board, it is our job to bring out the truth. Some photos of Khajuraho look like perveted sex and ashame some hindus. Mahatma Gandhi had commented about Khajuraho that it should be buried in the mud. On outer way it looks like beastality and perversion... then what about Ashwamedha Yagya where a queen is ordered to make sex with a horse ? so should we refuse Vedas to be part of Hinduism ?????
There are esoteric and symbolic meanings about Ashwamedha, which i told in mathangi's question. similarly these temples were made to bring out all possible perversion of human mind and to make it go beyond sexual thoughts of any kind. I heard the guru would sit inside the temple and wait for his disciples who have lost all interest in those photos and are ready to be initiated. Whatever is carved there is actually happening in the world now. People are having group sex, sex with animals, anal sex and what not in the name of free sex. Hindu rishis had long ago thought of such perversions and they knew that any day any mind of their disciple may come up with the thought of such perverted sexual thoughts... it was an idea to bring out those hidden desires out so that the disciple could go beyond such types of perverted sex.
However, this is simply one thought of one path of Hinduism. Sanatan Dharma is so deep and profound that hardly anything can shake its roots. Anyone is free to reject anything in Hinduism, and still remain a hindu. Like JayaG in her question asked...even if one does not go to temple, or read vedas or do chanting he would still remain a hindu.
Please respond if I could make it little clear or not. I would be so happy to discuss this by e-mail rather than on a public board.