Buddha, I know exactly where you're coming from. When I had my DA*16-50, I'd be using it mainly at the 16mm ends and 50mm ends and my brain just couldn't think in between.
I've since moved to the great Pentax prime lineup and haven't looked back. You may be like me in that you 'need' that restriction in order to get you to think about the composition and creativity more. I found the zooms would be the easy way out for me and I'd usually take it. Unfortunately, I found I couldn't control myself as much as I'd like to. This is probably all mental, but that's just the way it worked for me.
My kit consists of the DA 21 Ltd, DA35 Ltd Macro and the DA70 Ltd. Occasionally I'll bring along the DA 40 Ltd, but not often now. The DA*50-135 gets the nod when I have special assignments and I need the SDM, weather sealing, etc.
Try primes for a while and see how that works
You'll hate changing lenses, but the setup is that much more compact... and as mentioned, will push your creativity. OR your feet. Or both.