I can see the logic, but to be honest the build orders really only help you at the start of the game, for the very basics.
Sticking with Terran..This means building SCVs until you hit 10/11 supply, then build a supply depot, then a barracks next to it using the same SCV (building your wall here), then another supply depot again with that SCV. Whilst building your second supply depot, pump out 2 marines and also use another SCV to start your gas.
While you are doing that you should be constantly pumping out SCVs (I usually keep 2 queued up), and should also have sent out an SCV to scout the enemy. You can then stop producing SCVs for 30seconds only, and start your orbital command..then its back to pumping SCVs none stop.
By the time your 1st gas it up, and your 2nd supply depot is up, you should have scouted your enemy (this is probably at around a total of 15 units produced). What you do next will depend on what your enemy has done.
My advice is to practice the opening few moves, and then you really have to play it by ear. My personal favourite at the moment is to produce 2 rax, 1 factory (tech requirement) and a starport ASAP. Get the shield + stim upgrades, produce 3 medivacs and then load them up with marines/marauders - 2 marauders per medivac, rest marines.
Then head off and drop them on your enemies SCVs/workers..stim stim stim and within 10 seconds all their workers are dead and the base is wiped out..works a treat if your enemy has no AA. Scouting will tell you that, so shows how critical.
OR
If they do, the planetary fortress rush is a fun one. If they start to go defensive, they will probably stay inside their base, so I enjoy building a secondary base just outside theirs (in their expansion, slapping 3 bunkers around it full of Mar/maur, and tunring it into a planetary fortress. Eventually they get curious and come out to get splatted..a planetary fortress being repaired by 10 SCVs is near invincible against mid-game units
Again this only works if the enemy is going AA/Tutle though.
etc etc. The more you play the more ideas you will come up with, and the more counters etc..can't emphasize the importance of scouting enough. Its often worth playing the 3v3 or 4v4 games a lot too as you can learn from your team mates in terms of strategy. Keep at it, you'll get there