Yep, that has been my problem, too. And that's why I'm using LaunchBar for almost anything (launching apps, launching scripts from anywhere on the disk, etc.). No modifier keys needed, no fix key combo needed, it will learn from your typing habits. (But you also can set a fix abbreviation, in case you have to.)
Well, not via Spotlight, but with LaunchBar this is already doable. Please see this post and the ones below.
And, the even greater news, KM has gained some intelligence with KM8, so you can do this natively with "Trigger Macro by Name". See here.
It's working a bit like LaunchBar (or Spotlight), that is, remembering your last selections.
Yes, use this only when you are in text context (a text editor, word processor, or a text field on a web page, etc.)
The thing is, if you are typing the trigger string for example in the Finder, it is pretty uncontrollable what will happen: You might rename some incidentally selected files, or similar things. In addition, depending on your trigger settings, the macro will auto-press the Delete key several times, which is not something you want to do in the Finder or another program.
So, I would never use a Typed String trigger outside of a text input field.