Do I have to prime over spackle?
My dad and his dad were both professional union painters.  They taught me that for small spots of spackle on the wall, all you have to do is put a quick layer of regular paint over them with a brush while you're doing your cutting-in brushwork.  The spot over the spackle will be mostly dry when you go back over it with the roller later.  I know from personal experience that this works.  Also, there's no reason to prime if you're repainting a similar color.

I also know from personal experience that if you don't pre-paint your spackle as I described, you will be able to see it after the paint job is done.  The color may hide it just fine, but where the rest of your wall is covered with a slight texture from the roller, the spot that was spackled will be smooth.  It stands out like a sore thumb.  Hitting the spackled spot with your brush while cutting in and then rolling back over it later is all that is needed to fix that problem.