In this work we investigated different approaches and models used for the estimation of the charge fluctuation of solid particles in dusty plasmas. We compared the charge distributions inferred from these models and analyzed the consequences in terms of coagulation kinetics and particle size distributions. We especially showed that taking explicitly into account the discrete nature of the charging process along with the enhancement of ion flux due to ion-neutral elastic collisions result in significantly larger values for the fractions of neutral and positively charged particles, which affects the coagulation kinetics and the predicted values of particle density. We also showed, by comparing sectional and modal approaches, that the typical size distributions obtained in the studied plasmas may be well described using a bimodal distribution with a single size nucleation mode and a Gaussian large size mode. Such a possibility enables a great simplification of the aerosol dynamic description and open up an interesting perspective as far as multidimensionnal self consistent modeling of dusty plasmas is concerned.