At one time Clorox had the number of "drops" to sanitize a gallon of water printed on their label. Dunno if they still do, don't have any handy to check. Bleach may go bad, but it will be many years down the road. Like everyhting else, rotate it out and use the oldest bottles for the laundry.
The only iodine water treatments I'm familiar with is the little bottle of crystals sold to campers. You add water to the bottle and the crystals dissolve into the water, the concentration remains the same as the saturation point is reached and the crystals quit dissolving. There is a chart on the bottle telling you how much of the saturated liquid to add to a quart of water, it is temperature based.
Water needs vary depending on the person, climate, and activity. Keep a log of what you drink for a few days under various conditions and that will give you some idea what YOUR needs are. We also get a lot of water from the foods we eat, if your storage foods are different from your normal diet factor that in as well. Also figure in the dehydrated storage food water needs.