that's the thing about design- everyone thinks they can do it. It's true anyone can have ideas, and the best ideas come from people who use the tools, but a
good design requires careful, tedious, exhaustive consideration up front.
Take the barback for example. By putting in that finger choil, he exposes the back corner of the tang. This was probably already going to be an issue with this knife, as it is with the kayak. So that requires a change in pivot location, which requires changes to the tang and back spring.
Then, ideally, you should make a mock-up prototype of the knife. Carry it in your pocket for a couple weeks and see if it ever tears one of your cuticles accidently. Wait to see if it scratches your fingers as you reach for it. Heck- drop it a couple times simulating what could happen if you fumble it retrieving it from the pocket.
There's a lot to like about that knife- that secondary spear point is gorgeous, and I'm a fan of the swollen serpentine shape. I also like the general shape of that wharnecliff. That's where the positives end, however, and everything else kind ruins it.
EDIT: oh, before I forget- There's another issue to putting the bottle opener on the back of the blade. the blade can still be depressed further into the blade well- it's only spring tension that's keeping it in it's location. When you go to uncap a stiff bottle cap with that, you might end up leveraging the blade into it's own back spring.