One Big Text File Sure Sounds like OrgMode

Reading through Ellane's look at One Big Text File it seems to me that most of her issues could be solved with OrgMode. You can resurface notes on a set schedule with the Agenda feature. Events are simply headings with dates, and tasks get TODO added to the front of a heading.

OrgMode is easy for taking lots of notes under a heading, or lots of sub-headings as needed and you can filter the content easily by folding headings as you need to get stuff out of the way.