So this is probably a dumb question, but we just got a new front door for our house. It is primed white, and I want a white door, so do I have to bother painting it? Will it be impossible to clean otherwise? We will have a storm door in front of it.
I'd still paint it because it's coat of primer, which will look and protect differently than paint intended to be outside. Even with a storm door, it will still be getting some direct hot and cold from the outside.
Yes you need to paint it. Primer is only a thin sprayed on coat so the paint will stick to the metal. It will not resist the elements uncoated and won't clean easily (if you look closely the texture should me more like fine grit sandpaper than a smooth painted finish).
Yes and yes. You only need a small amount for a door so spend the few extra bucks to buy some high quality paint. It will save you from peeling paint in the near future.