Just remember that castille is a little different to make than other bars (use less water/cut right away/cure longer). Generally speaking. But it IS really nice just plain, no scent. And cheaper to make too (in Canada you can buy OO anywhere in fairly sizable quantities). And you can find castor oil anywhere too so you could add that at 5% for lather (are sensitivities to castor common? not sure).
@FarmScapeGoods - Holy moly that's a major sensitivity! Have you read the book "No More Dirty Looks"? It might be interesting to someone like you though you probably know most of that info already anyway

But there is so much garbage in store bought products, including contaminants and byproducts not even listed on the label.
So were your allergies the reason you started making soap?
Karri