I've always held the bar just outside of shoulder width, so neither 'wide' nor 'close'. What happens when you're using dumbbells and utilise your triceps more? The dumbbells will spread outward away from each other. This can't happen with the barbell, so it allows you to utilise triceps more than you would be able to with the dumbbells. Not saying it's using them more primarily, just the ability to use them more is available.
Regarding where you lower the bar, I've always been shown to lower the bar more towards the lower part of your sternum/solar plexus. Since this will be forward of the point of rotation (shoulders) it activates delts to stop the bar dropping forward, no? I've never seen anyone bench press in line with their shoulders, which is the only real way you could bring delt activation to a minimum....in my mind at least.