We employ coarse-grained molecular dynamics (CGMD) simulations and continuum mechanics methods to quantify the membrane-bending action of exo70. CGMD simulations show that exo70 produces the strongest curvature when bound to a key lipid PIP2, and when dimerized. To relate these simulations to experiments, we first quantify the deformation field generated by exo70 using CGMD simulation, and then investigate the resulting cellular morphologies using a continuum mechanics model for membrane bending. In the first step, we characterize the deformation field by directly analyzing curved membrane conformations generated by CGMD simulations of mutant and wild-type exo70 on mixed lipid bilayers. Monte Carlo simulations yield membrane morphologies which we relate to cryo-transmission electron microscopy images of exo70 remodeling a GUV. This model agrees with experiments which show that PIP2 binding and dimerization are necessary for generating membrane tubulues and protrusions. We show that this multi-scale model allows us to relate the structural as well as thermodynamic details of exo70 membrane-binding and self-association to the induced deformation field and resulting cellular morphologies. We also extend our studies to ENTH, BAR, and ESCRT family proteins. We show that thermal undulations in the membrane and cooperativity in the curvature fields, collectively drive the membrane into different morphological states (buds, tubules, etc.) that resemble those in cellular experiments in vivo and vesicle experiments in vitro. We determine the relative stability of the above mentioned shapes based on the free energy of these membrane configurations, determined using the methods of Thermodynamic Integration (TI) and Bennett Acceptance (BA), and Widom Insertion techniques. Results are shown for the case of Exo70 protein and ENTH, and N-BAR domains and also compared against measurements determined from experiments.