You are now in the minutia aspect. Many actually do not turn it down because of multiple reasons.
1. You may be offered the scholarship prior to college admission acceptance letters.
~ IOWS You get into TAMU, but have yet to hear from USC. ROTC scholarship in hand to TAMU
2. Come end of April/May you can request a transfer.
~ You get accepted to USC, but no scholarship. You can request AROTC to transfer the scholarship to USC.
~~ This is gut wrenching because at the same time colleges are requiring deposits. Do you double down on deposits? One to each school, or take the risk that the scholarship will be transferred.
I would also suggest you google USC admissions stats. Kinnem probably can tell you how competitive that school is for OOS admissions since his DS attends there.
~ Every state varies regarding % that can be admitted OOS compared to IS. VA, due to high property taxes, do not like ruffling the feathers of their constituents, thus the limit is set for IS vs OOS admissions. I know Maryland also does this, and too is in the 25-30%.
~~~ USC being a large university known nationally, you might have better odds coming from CA. They don't want all of their OOS students to come from NC, GA, FL. They want to spread the wealth, but still it can be competitive.
Good luck
PS.
Anyone that has been here for a decent amount of time will tell you many do not find out on the 1st board. Main reason why is that is the board they set the bar. It is not uncommon to be reboarded at least once. If you get it on the 1st shot, GREAT. If you don't, don't FREAK.