Yeah, dog hair gets everywhere. I just pull it off with tweezers. Clients don't seem to mind one or two hairs on the painting. I just tell them it adds extra realism.
I only paint from photos, and ideally the ones I take. Much easier to control and predict the final result. Drawing from life is challenging and rewarding, but not with dogs. That's just frustrating (to me).
Oils take a while to set up and dry, depending on: what/how much medium you add, how thick you paint, what colors, etc. In the summer, my paintings take 2-3 days to dry. In the winter 4-5 days.
Occasionally, I work in acrylic. Mostly it's illustration work, which is a lot tighter. Yup, it's frustrating, but it has advantages too. Making 3-day deadlines, and the ability to add colored pencil are a few.