Yeah, I think there is a certain natural attrition to it all - frankly though I think we should be very happy we've got this far! You are exactly right though, at this point we have all done what we can, the rest is in the hands of the gods, so to speak.
I can answer that one for you as my second and third choices were commissioned officer roles (leading to some quite tricky interview questions about the blurred lines between SNCO and a commission, that was interesting!), I was told in the interview that is absolutely fine, as long as your OASC score is competitive for those branches then if there is no WSOp roles available then you can request to be considered for that - might be worth a call to AFCO to add as a late consideration if that takes your fancy.