1) You really DO need to be making a minimum of 500 g total to minimize the effects of the imprecision of your scale. For the 250 g batches you've been making the difference between 5% and 0% superfat is about a gram of NaOH. With most kitchen scales having a 1 g precision, even a 500 g batch will swing within a percent or two of superfat as you stack the imprecision of every measurement in the batch. The truth is that because almost any lye you buy will have absorbed water already making it less "pure" so you are unlikely to make a dangerously lye-heavy batch of soap. What does happen, however, is that the imprecision makes it so that you don't really know what that soap you're using IS. You can't make reliable subjective judgement of it and you can't reproduce it if you find something you like.
2) Castor oil does not make more lather, it gives existing lather more longevity. There is absolutely no reason to go above 5% with it, as it begins to have detrimental effects, and in no case should it go above 10%.
3) Everybody has been critical of your fat choices, but you're not too far away with your last batch. A 33% soap with brittle/hard/soft oils is a classic combination, and you're just about there. In a vegan soap recipe, shea and cocoa butters can take the place of the "hard oil" component, and those two combined are about a third of your total. Since you've said your aloe butter is coconut- based it's a "brittle oil" for soaping purposes and combined with your straight coconut makes up another third. That leaves the apricot kernel third as "soft oil." That would make a very good soap without any castor at all, but since you've got it use it at 5% for better bubble staying power.
So try this. It has all your fat choices just tweaked to be more effective:
160 g of apricot kernel
80 g of aloe butter (BTW, if it's coconut oil based, use coconut in the calculator. The US Soapcalc is going to assume hydrogenated soy)
80 g of coconut oil
80 g of shea butter
80 g of cocoa butter
20 g of castor oil
If you want, play with the proportions of the cocoa and shea, or the aloe and coconut. Add some olive or rapeseed in place of some of the apricot if you want. Just keep the total of each category I described above at 160 g, and run any changes through a calculator to verify the lye.
Honestly, trust us and try these suggestions. No, we're not trying to be your Mom (or Dad in my case) but you did come here presumably for advice from more experienced soapers, right? These guidelines are traditional for a reason - they make good soap!
