The issue here is that the only build orders you can follow from beginning to end of a game are all-ins. There is no build order that says "take a 4th base at this point." I'm beginning to think the reason you slow down so much at two bases and don't even think about expanding again until an eternity later is because you run out of build order - nothing can hold your hand the whole way.well by build maybe i just mean a more specific focus and goal against zerg? like... i need a beginning/middle/end of mind train of thought so im not just... building units for the sake of it.
im guessing Marine/Tank/Medivac is the most common composition?
The goal against any opponent is to kill him. You can kill him early, or when you have an army that beats his (because Zerg mid-tier is kind of scary to use to defend Terran Marine/Tank), or when you've maxed out on the most badass army you can. However, only 1-base builds will tell you when you should be able to go in for the kill - the rest of them are intentionally open-ended so that you have room to expand and continue the game, or cut all worker production and set up an all-in from the point you're currently at.
In the direction you're going there is less I'm really able to teach you. You want clear actions to many specific conditions, which is why you're so heavily emphasizing a build order. That's not something I particularly believe has much of a future in any sort of unprepared (ladder, casual games) play.