Different versions of HTML aren't supported on different browsers, in this case the blink code can't work unless the browser supports a certain version of HTML. I think the most recent is HTML5, some browsers just don't support it :P
and yes, you can change properties of stories.
global script
$PAGETEXT := $PAGETEXT + "body background='URL'"
will change the background of pages in the advanced editor. body background=URL> will change individual page background.
Yes you can change link colors, page colors, logo colors, backgrounds, and if you're really dedicated you can basically do anything.
Also - if you use the font> code in the title of your page will change the font color, size, and face.
Reference.