Just to add to Chunks comments, most folks who go ROTC get out at the end of their commitment. Not all do, but most.
Trying to push for an ROTC billet will generally signal to Big Navy what your intentions are; most career-minded folks push for the FRS, Flag Loop or Flight School.
If you do take the ROTC job and elect to stay in, if you do not get a Master's that will be seen as a huge negative by pretty much every promotion and screen board you'll be up for in the future.
If you can also knock out JPME (in the event you have a few spare minutes between your job and your Masters), it may make your record look stronger on the DH board than some of the folks who do not have a Masters or Phase 1.
Good luck either way.