Here we go again. My opinion is anti-chemical. Liquids get into all the cracks, nooks, crannies. You don't need that. Sanding and/or blast. As Tiny said: it depends on how much surface rust you have in pit form. We have just had this discussion and it's all over the place. Everyone has a different opinion on this subject. When we get done with you, you won't know what to do. You are correct about removal and prime. There are primers that you can fill (as in: bondo) over later.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn