Those were my problems, and got to work on them. Now I know Gerber makes a tiny-ish pocket knife that uses disposable blades, and there are other manufacturers that make small folding knives without disposable blades. But those options are too heavy, I mean it's just a razor blade! How small and light can we go?
This small and this light:
The Ultralight EDC knife. Just what it says. It ways .66 oz or 21 grams. It is a fixed blade, 3d printed knife in ABS plastic. One side is ridged for grip, with a raised, tetxtured logo. The other has a beefy pocket clip, to index it in my pocket or use as a money clip. The cap is retained with a bungee cord, and can be opened with one hand. To make replacing the blade easier with cold or shaking hands, there is an indexing cutout to prevent accidental sticks.
I have been using it for about 2 months, and am really pleased. Durability is fine, despite some rough cutting tasks (carving wood, slicing poly pipe, extensive box cutting, etc). In fact it has totally replaced my trusty Swiss Army Knife. Sorry old friend. Most of my friends and family received one of these for Christmas.
There will be more info shared as it develops, but right now I am looking for production and distribution options. I think this is a marketable product.