Be sure you are setting the seam before pressing to one side. This may make the difference as the thread is being pressed into the fabric first. Then consider adjusting the size of the cut piece or the size of the seam. It's the finished product that counts and nobody will see the underside.
As to the disappearing points, I prefer to make blocks a little bigger and trim to size--and again, nobody sees the underside so you can fudge a bit to make it happen.