Serious Boot / Sleep Problems
That is a tough one and some of the symptoms seem to indicate hardware issues but the fact that it came back to life may put the lie to that conjecture. Since you already reset the SMC that is also out. More troubleshooting steps around power issues (including resetting the SMC) in the Apple KB here:

http://support.apple.com/kb/HT3964

Some of (all?) of these steps may be redundant depending on what all you have done.

It sounds like there may be a software issue as well. I use Onyx for general system maintenance and have found it works well and causes no problems. That may be worth a shot.

However once you have gone through that and the issue still remains you may have an intermittent hardware issue.

If you have upgraded the RAM yourself, you can try removing the DIMM you installed. Same for any HD/SSD upgrades you may have done yourself.

Failing that it may be time for a visit to your local Genius bar...