Those are some really good questions.
1. I don't THINK Jinton can disassemble Susanoo, but I think the user INSIDE the Susanoo can get killed
2. Wow, a really sharp question...... I honestly don't know, but it is a ninjutsu, so I guess so.
3. It is a Kekkai Tota, not a Kekkai Genkai, because Dust Release is a mixture of three natures instead of two: Fire, Wind, and Earth. Think of it this way. Is Magnet Release a KG? Yes. Is it always genetic? No. Is it still a KG? Yes. I know KG means blood line limits, but i guess KG doesn't HAVE to be through genes, but teachings as well. Therefore, Kekkai Tota is still a Kekkai Tota(?) I don't know how to phrase this, but you know what I mean XD.