We’ve got a rough sawn pine fence that is currently stained with a dark, oil based stain. We’d like to change the colour of the fence by painting it (maybe an off white or grey). What is the best type of paint to use?

I have an old standing seam roof with small holes in it on an early 1800’s house. I wanted to apply an elastomeric paint to seal the roof and then apply Benjamin Moore Ironclad over the elastomeric. Can I paint an oil based paint over elastomeric? I need the roof