Not unless the ChiComs gave them the recipe. Nukes are not by nature small items, and fitting on a missile actually is not an easy task. Even after BJ, the ChiComs aren't even good at it.
Not necessarily true. Although delivery systems are based on origninal Chinese design, the North Koreans have developed their own deliverly payload (satellites? yeah right.) program. The Pakistan's have Ghauri-II and Iran's have the Shahab-3 based on NK's (and China) designs, and could have added their deadly input.