Your strategy needs room for flexibility. Otherwise, yes, getting hit by something you weren't expecting will pooch you. Scout early and have some base defense.

Remember your own comment earlier; you need to wall in if you're relying on building up your economy.

I had a Protoss/Zerg team do this yesterday; 5 Cannons on one ramp and 6 Spine Crawlers on the other. Focus on making your cannon wall, then focus on pumping out Void Rays. Focusing on building money while half-assing your defense is a great way to die on the first assault.

Any half decent player that sees canons on your ramp will immediately know what's up and fend of your rays, or possibly just push through before you get them out, depending on their build. The only way to know how to respond to these things is to play and watch a lot of games, to a point where you have encountered any feasible build and/or cheese, and figure out how to act accordingly.

The units are prices accordingly; Cannons, Turrets, and Crawlers are relatively cheap because they may never fire a shot. Sure, there's a chance they may be a waste of money, but so is everything you build. And you'll be sorry the next time Dark Templars are merrily carving up your Drones.

I think at this point we really need to see some replays. If you have a superior economy then either you have too much money (ie: you aren't converting it into troops quick enough) or something else is going on here.

EDIT: For the hell of it I'm going to post that 1 hour 3v3 from work I mentioned earlier. Only decent players were me (as hot-pink Zerg) and my production manager (McAwesome). tooled is normally good as he's an old hand at Starcraft, but he was lagging so bad he couldn't do much. The other three were largely noobs. Nothing special, just entertaining to do 3v3s with friends.

Lego Starcraft:

I've a coworker who is about to get Stacraft 2, so I may buy it in the future (although I'd prefer to wait until it's a bit cheaper, still I don't know if my laptop can handle it though - HP Pavillion dv6000).

What the hell, was that Dragoons? There are no Dragoons in Starcraft II. ;_;

That replay is what I'm going to point to now when people tell me they don't need to make turrets/crawlers/cannons for perimeter defense, especially when everyone should know Protoss go Void Ray spam 50% of the time. You had money for 5 missile turrets minimum before the Voids arrived; grouped around your command center that would have been your win.

EDIT: I also shudder that Thomas probably thinks that was a rush ... on both sides.

On that topic, how are you supposed to scout effectively, i.e. without getting your scout immediately killed and learning nothing of value? Seeing a barracks going up at 2:00 hardly helps. You knew he was going to do that anyway. And any later, you tend to die before getting close enough to see any structures.

Nah, I've seen it once or twice in diamond. It's not really effective at all unless it's an all in such as this that doesn't get scouted.

And if it turns out badly, well, there are drugs for that...

http://games.slashdot.org/story/10/08/22/021243/Anti-Depressants-Used-Against-StarCraft-Addiction

Keep your scout around for more info. Don't be afraid of losing it. What he attacks your scout with is valuable information. More than that, if he's going for a reaper rush, for example, him cranking out a marine first to kill your scout delays his reaper that much longer for you to counter it. Scan, use an Observer or sacrifice an Overlord some time in to get further info.

To complicate matters, what your opponent doesn't have in his base also helps. That he seemingly only had a gateway and a cybernetics core at that point in the game should definitely raise some alarms.

Also, use turrets, cannons and the like sparingly. The more you use, the more on the defensive you are. 10 turrets in your main won't help defend your expansion. But your enemy's 20 marine army, for the same price, will happily attack it.

That said, if your opponent is slow and you think you can out-tech him, by all means wall off and try.

Edit: Hmm. I can't attach files. Dropping a file onto the area makes Firefox want to open it. Clicking the "Drop Attachments Here" as a button and trying to attach it does nothing.