Interfacial instabilities and wetting phenomena of phase separated colloid-polymer mixtures are addressed in this study. In particular, we study the viscous fingering instability in three dimensions, focusing on the role of wetting conditions and of thermal fluctuations. Furthermore, we investigate a related contact line instability, which leads to entrainment and subsequent droplet pinch-off. Finally, we study wetting phenomena at geometrically sculpted walls. We focus on the shape, the thickness and the radius of curvature of the adsorbed liquid film.