SMC issues on a MacBook Pro Thunderbolt

I've bought few months ago a MacBook Pro Thunderbolt 13' . As a Linux geek, I'm really happy with this computer, and it usually works fine. Unfortunately, three days ago, I wasn't able to restart it. It stucked without booting when I pressed the power button. I look on Apple website, and there was a procedure that describes how to reset the SMC , and I did that. My computer restarted (yeah), but unfortunately, I had problems with the display backlight (cf pic). So I stop the computer, and did the SMC reset thing one more time. I experienced problem to restart , but for the moment all the backlights issues seem to be solved. I'm now a little bit afraid about the reliability of this computer, and I have lots of question about this SMC I can't answer. - Why does that thing need to be reset? What is it exactly? As a geek, I like to know how my computer works :) - Can we reset it often without problems, or is there a limit on the number of time you can do it without harming the computer? I read differents advises ont he web saying 'go, on do it every week' or 'do it in last resort'. - If the restart problem still occurs, should I send the computer to the customer service for a global checkup? Thank you for your help :) Romain