I think that if you use salt to preserve food in some way, you should have both iodised salt and non-iodised salt in your storage. Table salt is iodised, you need the iodine for your thyroid gland. However, the iodine in iodised salt can discolor the food that you're preserving, especially if you use it for canning. So having pickling salt or canning salt in your storage is also a good idea.
As for sugar, I'm picky, I only buy pure cane sugar, that way I know it's not made from GMO sugar beets. But that's just me.