It better to look at the Requirement AI.xml in the Gamedata, i almost find all of it here ^^, include the VoidRay Speed, Nuke for Ghost Academy as well. The problem now is based on micro control, how to make the Roach burrow when moving. 
   In the ValidatorData.xml, it has the value when the unit burrow for each kinds of unit, maybe you can tinkering with it. ( I have been able to set the drone to burrow immediately, instead of running around when being attack, (unless it discover by an detector )