Sal,
I wish you well and I am not saying we all shouldn't try new things. But that is a very aggressive design for the wood. I don't think I could do it. Walnut is pretty weak in compression. A rigid-handled 54" bow, even for a 25" draw, is super short from any wood. Maybe osage and sinew would do it.
As for the splinter, definitely wrap it. You can reduce your weight to about 30# and probably make it work.
Good luck. Have fun. Wear eye protection and use a tiller tree
Next time, use the walnut for handle accents and tip overlays on an oak board bow that is 70" or so.