Regarding the x64 driver signing, I learned about the "fix" from Microsoft a few days ago.
At the moment, there is nothing I can do. An XdN Tweaker update will have a note on the X64 page.
Regarding the icon, I can put a 128x128 icon on the program easily, as Iconaholic provides that size by default. I'd like to include a 256x256 icon, but I haven't found one I like yet.
There was a point where most of the program size was its large icon. Having a 256x256 icon in it will make it pretty large again.