I wonder if this could be something for Alvaro .... even if he is long gone 
Thank you Frankb,
I'm not scared pressing enter, just a preference. What I meant to be "dangerous" is to send key strokes to the focused App. I don't want to use shortcuts as text expansions, I won't be on text-input context (thus it could be potentially dangerous, not only enter, any other key too).
Palettes and all this stuff are great, but they were not my first preference. Maybe I have to stick with them, but I'm still looking for other alternatives. You said that my requirements are probably impossible to achieve with any program but as a programmer, I don't see anything too absurd in what I was asking for. Anyhow, in case there is not anything like that, then I will use some of your suggestions.
Thank you for all your help people, this is a very healthy community.