Background Manager: Problems

Hello,

I am using Background Manager plug-in, which is great, however I’ve been having some issues. 1) my website is https://www.annapark.com.ar/bienvenidos
2) I chose to vertically stretch my background image and have it centered, however in some of the pages (Contact, for example), it doesn’t apply the image stretch. ???
3) At the bottom of my background, there is an image that should show up, but the content in my page is too long. Whenever I try deleting info, there is still a white space that covers my bottom background. Should I change my page margins? How?

Thanks for reading this.