No I'm not an atheist - I still believe in a God (not necessarily in the style espoused by the bible), but I doubt that he pays much attention to this world...or perhaps he is the world/universe etc
I think the purpose in life is to seek to be happy, and to hold values that uphold our communities as a whole...so I suppose from that perspective, it is still very close to christian values, minus the bits about loving God, converting people etc.
Like you, I've considered the possibility that evolution is simply guided by God...this seems likely to me... but that's not to say it's right (or wrong).
Personally, I look at the complexity of life and wonder how it could develop this way without intelligent guidance...but hey, that's just my opinion...what is important to me is, as I said, seeking happiness (I say 'seeking' instead of 'being happy' because happiness goes up and down, and, we can always improve), and finding/contributing values that develop community spirit.
Best of luck in your search for your personal beliefs
edit : btw, even when I was Christian I didn't have any real problems with evolution...the bible has it's contradictions, it has it's errors, and what most people forget is the Genesis story was handed down for (likely) thousands of years before it was recorded by moses...it's simply impossible to keep a story accurate over that period of time...and as you, I saw no reason why God couldn't simply have guided evolution (it's not a big issue to me...we are here now, and that's really what matters)