How did you approach the topic of wanting to study abroad with your parents?

I've just done my gcse's and I'm really interested in looking into colleges in the US but I have no idea of how to approach the subject with my parents. I talk to them but they still seem to see me as an eleven year old despite the fact that I'll be sixteen in less than a month. I have two older brothers who have both been through the uni process so my parents are already well versed in how expensive US unis are...
My school offers a talk on the American system which my Mum has said to go to when it happens, but I think it was more of a half-hearted 'yeah, you should go to that' but I'm really interested in the idea.

I know scholarships and grants are availiable but roughly how much does this bring down the cost?

Also, how much harder is it for UK students to get into US universities?

And are there any ways that I could improve my ECs on my own? Because next year I'll be doing all of the ones my school offers (writing for the magazine, senior literary society, politics society, debating society, senior book club etc) but I need more diversity (and trust me, sports is not a good idea and unfortunately for me, I'm not too hot on music, art or drama either )
Thank you and sorry for the long post!

This may be a stupid question, but can someone clarify the difference between need-blind & need-aware... I think I know but just to make sure

Need-blind means they don't consider how much you can pay when making admission decisions.
Need-aware means they do take into account how much financial aid you need. Basically the more you need the better you have to be to get in. Some schools only consider whether or not you need aid and admissions doesn't know how much you need. Williams, for example, said they do this.

Thanks for clearing that up! How good, on a rough estimate, would you have to be to need aid and still get in?

That totally depends on the uni, and even then its hard to make an accurate estimate. Your best bet is to look at the median SAT range of the uni and if you are in that, you already have a shot. Of course it's far from being all about scores, but they are good for a rough guide.

Would you say, then, that a need-seeking applicant's scores would need to be rather higher to make their admission "worthwhile"? Sorry I'm putting it so rubbishly, but the whole process is super confusing.