People have already replied to a lot of you wrote here, so I just want to add that Einstein emphatically did not reject quantum theory. Indeed he is probably on

People have already replied to a lot of you wrote here, so I just want to add that Einstein emphatically did not reject quantum theory. Indeed he is probably one of the people who could fairly be called the creator of quantum theory. What Einstein was rejecting with that quote is what we call the "Copenhagen Interpretation" of quantum theory. In my opinion he was quite right to do so, I do not know anyone in the quantum foundations community that takes Copenhagen very seriously any more. Einstein's qualms about Copenhagen lead the way to us understanding its flaws, and to people like John Bell putting us on a path to fixing some of those flaws. Einstein spent a lot of time looking for "something better" than Copenhagen, sadly he did not find it, but people who came later than him did (Everett, Bohm, the quantum Bayesianists etc). I'm going to slightly repeat what others have said here and talk about your issue with the uncertainty principle. Think about a wave travelling on the surface of an otherwise smooth swimming pool. The wave is an extended object, it is spread out. When we model the wave the fact that we don't assign it a perfectly precise "position" is a feature, not a bug of our model. Similarly I would argue that the uncertainty principle is not some barrier "blocking" us from seeing the true values of observables as we would like. It is a statement telling us that our mental model of things having a precise position and momentum at the same time is wrong, as wrong as trying to locate the wave at a precise position on the pool would be.