Leaving 1.5" from a point to the edge of a block has nothing to do with your seam allowance. It's not a technique you could apply to any star block, it is how that specific star block is cut and constructed. You would still use your same 1/4" seam allowance. When the block is sewn into the quilt, the star will 'float', in other words, the points of the star will not touch the adjacent block.
Here's an example. In this case the points are not even, but you can make them so. The points stop way before the edge of the block
http://fabricshopperonline.com/wonky-star-tutorial/
For a hunter's star I would look into purchasing Deb Tucker's rapid fire rulers. Here's her youtube demo:
http://www.youtube.com/watch?v=jWOS9KBDJgU