This UV filter frame was made by aviation aluminum. 

Yes, the lens cover is magnetic also threaded, and the lens can be screwed on directly, or it can be magnetically attached by a magnetic attachment ring or filter, which is a two-in-one function; 

Yes, the lens cover is magnetic also threaded, and the lens can be screwed on directly, or it can be magnetically attached by a magnetic attachment ring or filter, which is a two-in-one function; 

One more thing to check - if the end of the lens barrel on the powershot physically rotates when zooming or focusing, then the gradient filters won’t work as they will also rotate...just a thought! 

I've never used Hoya ND's, but I have GOBE, KERNEL, ZOMEI, and K&F ND filters. Out of all of them, I like the K&F the most because the colors look great out of the camera and they don't create a vignette around the edges like some of my other nd's which I hate. Because of the great out of camera colors, it gives you more to work with on post-production when you shoot on a flat profile. Also, I've used them during night photography on bulb mode to do light painting and the 4 - 6 stop ones work great for this. Overall, I think for the money the K&F filters are worth it. Awesome product!