Questions about the LH-X10 Lens Hood for the Fujifilm X10

I'm confused about this so I'm hoping that someone can definitely address this once and for all. I was set on getting this lens hood because it'll allow me to use a high quality filter. I don't want to go and use a sub-par 40.5mm filter on the X10. However, what concerns me is when someone told me that using this lens hood, dust can enter from the side and back and stick to the UV filter's back. Is this true? Is there no way to ensure a complete seal once the UV filter is attached to the lens hood?

Can someone also tell me how much space is there between the front element and the UV filter once it's attached with the lens hood?

Thanks!