I would suggest that you include the direct x installer in your final release of PA. I think that a lot of my friends would not know what to do, when they get the error message about the missing directx dll.
Game itself doesn't require DirectX at all right now. But it's UI middleware Coherent based on Chromium Browser which using DirectX on Windows for OpenGL ES emulation: https://code.google.com/p/angleproject/ And I doubt they can remove this dependency from Coherent because it's damn hard to modify such large codebase like Chromium, otherwise it's will lose part of functionality like WebGL which might be useful for PA mods.
