Hello. You should definitely apply. I was just accepted into UCLA's MSW program and I applied directly from undergrad. I have done volunteer work throughout high school and college but have no direct social work experience. Judging by your stats you look like a strong candidate. Let me know if you have any more questions or want more info.
I had the same decision to make and went with UCLA. I was not very happy with USC's process. UCLA sent me financial aid info a couple days after accepting me but for USC you have to officially accept and send in a $200 deposit before they tell you how much aid you get in May...
I received acceptance via email about a month ago but don't get too worried yet because the last people they accept wont be notified until early April. Hopefully you will hear back this week. I have a good friend in the same position.
USC notified me by mail 2 days ago.