Um, maybe I'm misunderstanding you but...
... you are aware that when you change the chart size, it still has all the same data right? You can drag it backwards along the timeline to "zoom in" on earlier trading history. So it makes sense to keep it the way it is.
What I think they need to do, at the very minimum, and I suggested this to them: put the charts above/below each other, and zoom them the hell in. With as many orders as there are, the market depth chart is almost useless except for the outliers.
The Y-axis doesnt always need to range from zero to 30.
http://bitcoinity.org/markets?theme=dark this is nice, what are the red and green shaded areas in the trade chart? and what do the red and green bars in the middle of the depth chart represent?
is there any tradehill equivalent of
http://bitcoin.clarkmoody.com/order-book/ this interface for mtgox is brilliant for gauging depth with actual figures better than charts i think