It's the South so rush in general is usually very competitive. The larger Florida colleges have very competitive rushes (UF, FSU, UCF). The problem is that there are more girls coming through rush than there is space in the sororities. But, we are adding more. When I went through (and when XOAlumXO went through), there were only seven sororities. This year, there will be nine sororities participating in formal recruitment. The tenth sorority will be colonizing about a month later and will be doing an informal recruitment.
But, unlike many schools, we don't have a cap on the number of members in a pledge class. The pledge class size is not determined until prefs. UCF panhellenic divides the number of sororities by the number of women returning for prefs. That number gives the quota. This is why UCF tends to have very, very, very, very large pledge classes. Last year, quota was 67 and the year before it was 71!

The good part about that is that the chance of girl to not get a bid at all (snap bidding included in this) is very low.
As for if you have to live in the house:
I am not aware of any UCF sorority that requires their members to live in the house. ZTA has the most rooms out of all sorority houses and there is only space for 40 girls. With a chapter of 180, there is no way we can have a requirement to live in the house! I know for sure that ADPi, KD, AZD, and Tri-Delta do not require the girls to live in the house and I am 99.9% sure Pi Phi doesn't either. So, you don't have to worry about that if you have an off-campus apartment.
UCF was voted as the number one greek system in the state of Florida!