Well I'd say if you rely too heavily on any rigid system it's going to hurt you eventually -- so you're pretty much right, although I'll play the devil's advocate a bit.
Unless it's a faster blitz game (<5 minutes), I actually like to think in terms of imbalances before asking myself "are there any emergencies on the board now." Because sometimes, an emergency is illusory. After you break down the position sometimes you see you can drop that pawn or piece, or allow terrible looking doubled pawns, or accept a cramped position or bad bishop because what's important in the position has nothing to do with what may seem terrible on the surface.
Of course I can say that and then in tactical situations of course I'm immediately assessing what my opponent's last move threatens. Or if I've seen a position before from memory I may already know I can't allow c5-c4. And from my own style/experience I may skip or transpose steps in my thinking so we're pretty much back to any rigid system is bad. Although unless the position is tactical or you've had a lot of experience with the position to know what can or can't happen, I'd argue that nearly every time you're going to want to start with imbalances.
Here's a position that I thought made a good example after the following discussion in the "what book are you reading right now" thread:
Just got Silman's How to Reassess Your Chess Workbook. Who here has read it? Any advice on how to read it? What'd you get from it?
A great book that really shows you the limits of Silman's system, but also helps you really use it...{snip} The challenge is to figure out how to use Silman's methods and blend them with your own way of thinking to arrive at playing stronger chess.
I'll start another thread with an example
So, here's an example -- this is problem 21 from the imbalances in the opening section of the workbook (see moves list for notes):
According to Silman, this position (as usual) is best understood through an understanding of the "imbalances."
Well of course correctly assessing a position is essential and imbalances are a big part of that -- but if you try to lean really heavily on imbalances and make them the alpha and omega of your thinking -- I think they get in the way as much as help.
So, here, I don't think dxc5 is a particularly hard move to find so long as you begin with: What is my opponent threatening, what's his best move... do I have any 'emergencies' on the board, now? If that's your starting point (and IMO it should be) I think c5-c4 jumps out as a very ugly move you must prevent.
The imbalance Silman sees in this position is White's development advantage -- which is a 'temporary' -- dynamic advantage. You need to play actively to make use of it. A strong edge in development typically calls for a search for attacking tactics including sacrifices and typically opening up the position favors the developed player. Conversely, when you have a development disadvantage it is usually a mistake to open the position and locking it up could be good.
Considering the imbalances in the postion I think playing dxc5 fits the imbalances well. -- dxc5 opens the position which is how White would like the imbalance handled. And that's how I often like to use imbalances... they are my 'kibitzers' who say, "oh, so you like cxd5 for tactical reasons ?-- well it makes sense with the overall strategic demands of the position too, so it's probably an okay move..."
But would considering imbalances first and foremost really lead one to find dxc5 efficiently? Maybe... but it's a fuzzy way to go in my opinion. It's very easy to miss the c4 push if you stay up in the high level clouds thinking about development and opening things up in general, or searching for some attack that isn't quite there yet. I think there has to be a 'dialogue' between the high level thinking and the concrete variations. Silman rarely (ever?) says this in his text, but i think it's actually all over the place in his practice.
(I have more to say about Silman's teaching... but I'll save it for another post...this one's long enough as is.)