Einstein didn’t have anything to do with the bomb. Good thing he managed to escape the Nazis though
Even if he was directly responsible for building the bomb, he didn’t drop it on anyone. So no, assuming that hell exists, I don’t think Einstein has to worry
Einstein famously wrote a letter to President FDR suggesting that the US makes an effort to make the atomic bomb, but he grew to regret his suggestion.
Physics students and graduates have to grapple with the consequences of their work. Often the work of scientists ends up in the hands of politicians (who order their military to use it).
After John Podesta got his email hacked (revealing private matters of Hillary Clinton, whose campaign he was managing), Hillary raged at Russia and threatened them with nukes. One must temper rage if one is to control nukes.
You are right, however, that Einstein had initially pooh poohed the idea of quantum mechanics (claiming that God didn't play dice with the universe). Quantum mechanics is about matter being made of light of random position (still in the same energy level).
Later Einstein accepted quantum mechanics and actually contributed to it (Bose-Einstein statistics).
The Einstein Podolski Rosen Paradox modified the Heisenburg Uncertainty Principle from "random" to "random and statistically independent" variables. The argument goes like this: Suppose a row of "spin 1" particles was split randomly, so that the top was a set of random spins, then the bottom (which is 1- the top spin). This means that the bottom row is also random. But, clearly the top row is statistically dependent on the bottom row.
The fictional Einstein Podolski Rosen Bridge (from the TV show sliders) was the justification for sliding to parallel dimensions (remember, it is fiction). So, don't confuse the two.