Number two is something i figured out a while back but have yet to try. I think you can use an imagemap (GIMP can generate one pretty easily with Filters>Web>Image Map) and instead of putting links in parts of the image, use title text. I haven't made an imagemap in a while but i think that should look something like:
<map name="example">
<area
shape="circle"
area="75, 45, 75"
title="Hover text here">
</map>
<img usemap="example" src="whatever.gif">
It's not perfect, since you still have to hover over an area for a couple seconds to get the text to appear. There might be something you can do to make that happen faster but i don't know what.
I'm not sure how you could make the div and iframe scale together. I'm sure there's a way with CSS, but i'm not great with that stuff. Good luck.