Abstract: Studies on nonclassicality, entanglement, and decoherence of quantum systems are some of the key areas of research in photonic quantum information science. Analysis and development of such features based on resource theoretical frameworks have unveiled a new avenue in the last decade. Quantum resource theory is perhaps the most revolutionary framework that quantum physics has ever experienced. It plays vigorous roles in unifying the quantification methods of a requisite quantum effect as well as in identifying protocols that optimize its usefulness in a given application in areas ranging from quantum information to computation. Moreover, the resource theories have transmuted radical quantum phenomena like coherence, nonclassicality, and entanglement from being just intriguing to being helpful in executing realistic tasks. Along with the rapid growth of various resource theories corresponding to standard quantum optical states, significant advancement has been expedited along the same direction for generalized quantum optical states. The generalized quantum optical framework strives to bring in several prosperous contemporary ideas, including nonlinearity, PT-symmetric non-Hermitian theories, etc., to accomplish similar but elevated objectives of the standard quantum optics and information theories. In this talk, I will discuss our developments in the given context and their usefulness in the areas of quantum information theories. Certain remarkable features of quantum optomechanics within the field will be discussed alongside. More specifically, I will come up with realistic and experimental ideas for cavity optomechanics to generate resourceful states and their utilization in some of the areas of photonic quantum information theory.