You've already submitted your UCLA application, so you will either get an admit, or you won't. Asking about your chances now is a bit of a moot point isn't it?
As for USC, so long as you put in a strong written application and you interview well, you should be competitive.
Also, I don't understand why you would be so worried about your job situation. You need to do what you need to do. Just tell the truth -- it's far more elegant and compelling and engaging than trying to come up with some convoluted "spin" of a story that will sound like BS to someone. The lack of authenticity, being fake, trying to pull a fast one on someone - ESPECIALLY when the adcom can sense that you're trying to do all these things is far worse than simply telling the truth as it is.
Finally, you can't submit additional stuff if you've already submitted the application. The adcom won't read it. That's why there's a submission deadline - otherwise, everyone can start jamming additional material in the adcom's faces at every opportunity in the false hopes that it actually helps you (it actually makes you look bad because you'll come across as a bit desperate). For UCLA, you've submitted your app. Wait. Hopefully you'll get an interview. If you don't, there's nothing you can do about it. For USC, focus on what is in your control -- and do the best you can on the written applications.
I understand the anxiety you may feel or the lack of control sometimes when it comes to this process -- it's just a matter of separating out what you can control, and what you can't (and not letting your anxiety cause you to cloud your judgment and making you needier than you should be, or "spinning" a story when you're best off just coming clean).
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