They're not kidding, stearic will cause CP soap to seize in under a minute. I used it in the very first batch of soap I made, and while it is a nice soap and lathers beautifully, there are huge stearic blobs all through the soap because I could NOT get it mixed fully once the lye hit. I'd recommend holding the stearic out until you get your lye mixed into the other oils and they've come as much to trace as possible.
I think if I were going to tinker with that recipe, I'd up the shea and cocoa butter both to 20% (or even 25% each, and take it out of the olive oil), drop the castor to 5%, keep the stearic at 10%, and drop the olive oil to 45%. And, as shunt said, switch your lye concentration to 33% unless you decide to hot process the soap, in which case your water amount is fine as is.