For lye, in terms of purity, from highest to lowest: food grade, lab/tech grade, drain cleaner. I have used both food and lab grade lye in making CP soaps, and have not noticed any difference. Never tried drain cleaner, not because I am a snob, but simply because it is not readily available near where I live. All grades of lye may contain impurities such as aluminum, but so will that piece of pie baked in an aluminum pan.
Since I also use lye from time to time in cooking/baking, it is just simpler to keep food grade lye around instead of having two types. The difference in costs is not that much. And like lsg, I get my lye from Essential Depot as well. In a pinch, when I run out and I must make soap, there is a local science/lab supply store I could run to.
Whether you use organic or conventionally produced oil is a matter of personal preference. Conventionally produced oils might contain a negligible amount of herbicides/pesticides. The question is whether the difference in costs, compared with the reduction in risk (or perceived risk), is justified - and it is something for an individual to decide. Same with conventional vs. sustainably harvested vs. no palm - it is a personal decision. How the oil is produced also matters. Some are cold pressed (IMHO, way too expensive for making soap), some are solvent extracted. And of course the oils that are solvent extracted may retain a minuscule amount of the solvents, such as hexane. Should you avoid it? Again, it is a personal decision. I don't, because the amount is too tiny for me to worry about in a wash-off product. You are probably being exposed to hundreds if not thousands times more of these chemicals having a restaurant meal.
I judge the quality of essential oils with my own nose. While some people are happy with the EO from low cost suppliers, I have had several bad experience with cheap EOs. They smell fake and chemical-y to me. At this point I have made the decision to avoid the cheap ones and go scent-free when I cannot afford quality EOs. Other seems to be fine with the EOs from places I avoid; and many people are fine with using FOs as well.
They way I look a it, we are bombarded with all kinds of chemicals in our daily life. For health and other reasons I like to minimize the exposure but it is impossible to avoid everything. How far would you go and how much money should you spend to do this, is, ultimately a personal decision.
