Fluctuations and dynamical collisions can be responsible of non standard distributions observed in many astrophysical environments or astrophysical plasmas. In fact, since Coulomb collisions are the means to achieve equilibrium, plasmas are typically not in global thermodynamic equilibrium. We examine three different and linked problems whose solution is needed to determine parameters concerning evolution through metastable states of stars and other astrophysical systems: role of temperature and density fluctuation, electron screening of nuclear reactions and penetrability, evolution and comparison of different collision frequencies to establish the degree of deviation from the global thermodynamic equilibrium usually assumed. We indicate how these problems should be treated in a generalized environment by means of the q‐generalized statistics and evaluate the collision frequencies, confirming that deviations from a global equilibrium cannot be neglected in these systems.