I second using the safe razor, albeit I would recommend using different ones for face and balls. The reason is that I assume that an ideal and universal razor may not exist, the ones I tried are usually either better suited for the body, or more comfortable to apply to the face, that is if we exclude those that are equally bad for everything.
Regarding the dulling of the blade, it may greatly depend on the brand and quality, so some experiments are required ¯\_(ツ)_/¯
Octopus TV-shop delivers to an elderly lady that forgot to buy pickles for the salad. Nothing out of the ordinary ¯\_(ツ)_/¯