curious

yes and yes

yes and yes. It's unfortunate for the latter but don't let it stop you :)

you haven't even got into ucla yet, don't worry!

I'm in a top house. So here is one perspective...
1) Race will not be an issue with us... African American or otherwise. I have never heard of anyone in my house saying anything racially negative. I have friends of other races and so do most of the people I know. I can't guarantee there aren't people in sororities may have a problem with it though. However, if they cut you because of race... You would not want to be there anyway.
2) Being a legacy will get you special consideration, but it won't get you in. First, every sorority has minimum grade requirements, test scores, and resume. If you are accepted to UCLA, you will likely look pretty good on paper so make sure you show it in your app.
3) Practice your people and conversation skills. Lots of girls are cut because they aren't naturally able to talk to strangers. Sometimes they come off as snobby or uninterested when in fact they may be shy.
4) Keep an open mind. If your legacy house cuts you- so what... You will find a place. I went in thinking I absolutely wanted one house and was pretty sure the house I am in wasnt for me. Meeting the girls absolutely proved me wrong and I changed my mind. That being said, I could have been happy in most of the houses. There are many types of girls in each house. The girls that end up unhappy are the ones that don't trust their gut and pick houses based on stereotypes vs. where they truly belong. This is a heart descion... Not a head.

it can be pretty random

i dont think it matters at all. i am in a top house and i have never ever heard anyone say anything about someone during the rush process considering their race.