[deth]

Having a CC first as a standard build sets you up to be exploitable. Zerg can adapt with early pools after playing you a couple of times, or shit, even a drone/ovie scout and set themselves up with 3 Hat before pool and you lose your entire advantage (see: Life vs Cure)

As to the other builds, hard to say before you write them out but a 4 minute blind ebay in TvP is going to delay timings and lose you map control if you're rushing turrets or just rushing an upgrade, unsure what you mean at this stage.

And a gas first banshee in TvT is very exploitable, gas first is still a great build but you can't be stubborn and JUST do banshees every game. Have to learn how to scout and adapt towards every possible situation with different unit compositions. If you're doing gas first banshee blind then you're going to lose a LOT.