Do you really think UK culture is so different from American culture that you'd contribute an uncommon perspective in the classroom? That is the question you should be trying to answer when writing this essay. What are you contributing to the classroom?
Ugh I've disabled the option to release my academic information/LSAT scores to schools a long time ago, but I think it's too late. Worst part is, I'm Canadian and won't be applying to any American schools ;(
There isn't one specific answer. I know of 2 people who received Columbia waivers. Their scores ranged between 167-171. One of the applicants was a URM, so not sure if that changed the calculus at all...