That sounds like a neat idea. i would go for the line chart with expenses line and income line so you could easily see where they intersected. It seems like it should be easy to just have 1 chart that showed an entire year(or more?) projected. Projection for a month is easily seen on the calendar itself. Projections for shorter than a year will look the same as for a year and just leave empty space on the plot.
Also would be interesting to consider allowing more than one account on a chart. If, for example, you had a money market account that is used for tucking savings into as an emergency fund, by setting up a repeating entry to move money to that account, you could look at it’s projected growth along with your regular cashflow lines. Have to think about that one. It might cause more grief (for Eric)than it’s worth, but it could be handy for some people. Anyone else think multi-account plots might be useful?
Over all, the chart is a good idea I think.