I agree with QM. The biggest problems I've had with points were when I've tried to use a "scant" 1/4" seam. Try a generous 1/4" for the triangles. Then a standard 1/4" seam for your sashing should work. With the 1/4" foot for each of my machines, I can move the needle 1 position to either left or right, so that's how I do it.
Yours are at least as good as the first quilt I made with that pattern. I suspect that some of your seam allowances are a little bit small. For what it's worth, the neice for who I made that first quilt with this pattern wrote me, "I didn't know you loved me that much." Don't get discouraged. You are on the right track.