Heck, my pc runs United Devices 24/7 for years, no problems with that, I havent even had a fan fail yet. My 12 year old Powermac 6100 has been running as a webserver for years too...no problems there. I'd say you're safe, computers are designed to be used.
I have a Wallstreet Gen 2 and recenlty it has begun displaying artifacts when you move the mouse, or around icons and text. They will dissapear when you go into sleep, and return once you start moving the pointer again. Is this signs of a dying logic board?
To clarify the artifacts: They are...