Paint quality is determined by the grade and type of pigments, resins, and how much water is in the can.

Enamels are less likely to be damaged by cleaning than are most flat latex paints.

Painting won't hide cracks and holes in the wall. If the wall is uneven, in any way, take care of this first otherwise it will stand out when you are done painting. The paint will even make it shine through more so. If you don't want to highlight those cracks, holes and uneven areas, fix them first.