Design is a highly personal decision and once you step way from the retail board design track there’s always going to be a certain amount of “try it and see what you thnk” involved.
With that said, I have a couple observations about the design that you may or may not intend to be doing.
Firstly, the rocker. What you have there will surf. But if one of your comments about the hypto krypto is that you think the rocker is too flat then I’d like to point out that you can’t get too much flatter in the nose in a 5-8 length than the 3.3/4" you’ve got. If you bump it up 1/4" to 4" that will be a nice moderate rocker. Some builders might add more than that in a 5-8 length. Be mindful of the point that the rocker in your design has to more/less fit the rocker in your blank- at the length that you’re cutting it. . I normally pick the blank and any rocker adjustments first before I commit to a specific rocker curve in my design.
If this is your first board then try to stay away from having to significantly alter the blank in the rocker. Blank comes first. If you just follow the blank’s rocker that’s usually a good starting point.
Secondly, If you’re going to go for a swallow tail then you’ll need hard corners in your design at the tail. Maning, take the curve out of the tail tips. We normally cut the swallow as one of the last steps in shaping. You’ll basically cut the swallow after you’ve finished shaping everything else. Personally, I wouldn’t suggest a swallow as a first shape, especially if you’re going to glass it yourself. Getting that inside corner clean in both shape and glassing takes some additional skills.
Thirdly, In your shape it looks like you could use a little more curve in the front 24" so there isn’t that corner between the nose cuve vs the middle curve; and similar for that bump in the rear quarter at 24". A subtle adjustment outward from the tail tip control point will make that curve fit your middle a lot more cleanly. Unless we’re adding a hip or a bump or wing to turn off of in the rear quarter we’re otherwise always looking for the nice unbroken curve from front to rear. It’s always all about the curve.
BTW, a 14" tail is probably too narrow for a 19" wide board or a 160# surfer. 15" for a 2+1 or quad setup is pretty good and that can readily be pushed to 15.5". It you were heavier I might even push it to 16". As far as the curve goes, more curve is for control but that control comes at a cost of speed and drive. So for a 5-8 length you might do better with a flatter curve. Just remember that small adjustments will make a big difference, so try to avoid doing anything extreme.
What’s cool about the CAD programs is that you can tweak a design endlessly before committing to it. Most programs have a 3-D simulator which enables you to render your design in 3D and rotate it on a 360* basis to look at it from all angles. Just to illustrate what I’m talking about in making adjustments, I took the liberty to run your template up and tweak the curves a bit and to square off the tail block a bit for the swallow tail. I’m not suggesting you use this particular iteration, nor will I give you any numbers because after all, we want you to do your vision and your ideas, not someone else’s.
