I also stored unit actions (such as build Probe, warp in Pylon, etc.) as functions within each unit. As I wrote the functions, it quickly became apparent that a huge number of functions are identical and should only be written in one place.
This build shows me the viability of storing unit actions within the function and keeping track of unit timelines within the unit, but also shows the weaknesses of displaying the timeline when I have to scan every unit for every second to see what has been done. It still does not take into account that you need a Gateway before you can make a Zealot, but I chose to not pursue that in this build when all of the flaws of this build became apparent. It does, however, take into account queuing and will not let you build more than 1 Probe from a Nexus at any one time.
I will begin my next iteration very soon and hope to have that online within the next few days. Each iteration definitely teaches me a lot about what will and will not work. I am still very far from a final build, but I still think it is possible to get the final build online before the game launches on Jul 27, 2010.