If I remarry and the man I'm marrying owe on child support do I have to pay his child support I'm on disability?

No you are not directly responsible for his child support but you need to consider what the situation really is and how its going to affect what your going to do.

No, I think you don't. At least I was told when I married that my husband's income would not factor into CS calculations, so I'd reason the opposite would be true (the obligor's spouse's income should not be factored in).

No, you do not have to pay, of course he wlll be paying and I assume you willl have to help with other bills, if he does not have money to pay

The question, I think, hinges on what "paying" means. If household income is considered in a State then, yes, indirectly the spouse's income from any source factors into the equation.