Travis Norsen has an excellent textbook on quantum foundations, certainly suitable for someone at your level. It covers everything quite well except retrocausal models, which are explicitly set aside. For that topic, you might look at this Rev Mod Phys article which summarizes the motivation for using some future-input-dependence in models of quantum entanglement, as well as describing some of the retrocausal models in the literature.

Quantum Gravity, I'm not so sure about; I'll leave those recommendations to others...