I want to repaint my basement walls, and it's proving to be a more difficult task than I expected. I started by scraping off loose paint, but discovered that the walls are possibly coated in stucco. The photo show the results of the scraping. Am I correct that this is stucco?

Do these areas need to be patched/smoothed over before painting? With what?

In another area of the wall, there is mortar that is missing. What's the best product use to repair that?

I believe the paint that is currently on the wall is Drylok extreme waterproofer (the previous owners left bucket of it when I moved in), so I was just going to repaint with that. How does that factor into what I need to do for the prep?