Almost all of the ones I have met and I have met a few, none would let you cum in their hair (except for one which was a very special arrangement and expensive as well).

Yes, brushing, praising, rubbing and just seeing their sexy naked bodies covered with their long luxurious many is widely appreciated by all of them (as you are not humping them like a dog as soon as you have met them). Hair pulling in doggy (standing, on the bed), them on top with their face or tits (whichever way you prefer) covered with hair while you fuck their brains out is also welcomed.

Hope you get the picture.