Question: Is it possible realistic to get picked up for OCS as a potential Nuke Officer during the training process?
It is neither possible nor realistic to get selected for OCS for any program while in the training pipeline. You need to be further than 1 year from transfer IIRC (which you never will be while in the pipeline as all schools are 6 mo or less), and you need to have a CO's endorsement that is a little stronger than 'he has a high gpa in power school, recommended for commissioning program.'
Also, you're not eligible for nuke officer, period, because you don't have a year of calculus-based physics.
The option to commision as a nuke officer out of the training pipeline is reserved for STA-21 applicants. You are not eligible for that program because you already hold a degree.
It is generally harder to get a commission via OCS after you enlist if you are otherwise eligible. With your accounting degree, you are eligible for any unrestricted line job outside of nuke, as well as supply corps which would allow you to use your accounting degree in a limited way. To have a chance of being selected for OCS as an enlisted Sailor, you'll need some EP evals, leadership collateral duties, and strong LORs from your chain of command. Those don't come overnight and you can't obtain them while in a training command. If you want to be an officer, withdraw your DEP application and go visit an officer recruiter, take the ASTB and start the application process.