True to their word, well, their final word at least, The Mac Shack did indeed finish repairs yesterday and I was able to pick it up. I was so surprised when I called them and they said it was ready (ummm.... why didn't they call me?) that I asked, "Really? It's really ready? And it's working now?" The guy must have thought I was crazy, but disbelief is the mode when it comes to the iMac. I rushed up there and picked it up, brought it home and let it just sit and run the screensaver for a couple of hours with no problem. I proceeded to use it a little, and after nothing crashed I did some heavy iMovie work on it; yesterday was the deadline for a video project for one of my clients, I finished it about 11:30 last night! But thankfully I was able to finish it and meet their needs. 

It all seems to be functional. It comes out of sleep mode, the fans don't run wildly, and I haven't seen a single spinning beachball yet. I have heard the hard drive making more noise than normal, but honestly I think that might be due to my paranoia of spontaneous combustion more than there being a valid concern. I did have to re-install iTunes which is a bit puzzling since they didn't do anything to the applications on the machine, but it worked upon re-installation. So, for the moment I think I can safely say it's finally working. Let's hope it stays that way!