technova76
1 - I'm afraid it supports photos only, not for video, you can search for a 3rd party extensions which supports video like that.
3 - That patten is a background image: /templates/ja_donate/images/pattern/bg-title-lead.png
The relevant css code which defines this background is:
.error-code::after {
background-image: url('../images/pattern/bg-title-lead.png');
}
You can change with your own image or if you want to remove it, set this 'background-image: none;' property
5 - You can override this css:
.nav > li > a.button-highlight:hover,
.nav > li > a.button-highlight:focus,
.nav > li > a.button-highlight:active {
background: #326f9a;
}
change the background color to your desired color.