Easier way to manage vertex colors

I’m midway through CGcookie’s CUBICITY course. I’m learning a lot but i really struggle with textures. The instructor clear has ‘his eye in’ from years of experience. I really don’t like that I can’t simply sample the vertex color from another object without changing the viewing options. I also really hate managing vertex groups and constantly switching back and from from edit mode and vertex mode and selecting vertex groups. I endup going through the same process repeatedly just because i missed a face from my selection

is there are easier way (extension or something) to manage painting with vertex colors and palletes? I’d like to assign the same material and vertex color to a vertex group at the same time without all the faff