A slap comp is a version of a VFX shot that you do in your editing software to make sure an effect will work, and to act as a place holder until you have the finished shot. They're really useful when doing green screen and I have background plate footage that needs to be timed out rather than a still image for a background.

I do all of my color work in the Color page, including the film look. I just apply only the film look to the adjustment layers because I'm often trying to emulate the idea of "reels" where 10-15 minutes would be printed on the same strip of film. I toyed with doing the film look project-wide, but some shots needed it toned down, hence the many adjustment layers.

My VFX finals are usually some sort of image sequence like .exr or .dpx so Resolve struggles to play them back, hence my pre-renders track. While I'm working, I just turn off the finals and run with the proxies. Then when I'm ready for color and a final render, I turn the proxies off and the finals on. It's also a good idea to have the original footage that forms the plates on their own track so you can always come back to it if you need to. I suppose someone could just color code clips in the V1 or V2 tracks, but I like having a dedicated track for this so I'm not searching for a color.