Nontrivial mixtures of an arbitrary pair of a pure entangled state and a pure product state in any bipartite quantum system are always entangled. This is not the case for superpositions of the same. However, we show that if none of the two parties is a qubit, then all nontrivial superpositions are still entangled for almost all such pairs. On the other hand, superposing a pure entangled state and a pure product state cannot lead to product states only, in any bipartite quantum system. This leads us to define conditional and unconditional inseparabilities of superpositions. These concepts in turn are useful in quantum communication protocols. We find that while conditional inseparability of superpositions help in identifying strategies for conclusive local discrimination of shared quantum ensembles, the unconditional variety leads to systematic methods for spotting ensembles exhibiting the phenomenon of more nonlocality with less entanglement and two-element ensembles of conclusively and locally indistinguishable shared quantum states.