caps? hmmm, if they look ok ... then they're probably ok.

clicky-floppy? that sounds bad, especially if its a continuous clicky ... the drive must think there is something in there to read. The heads might be dirty. I'd blast some compressed air in there, use a FloppiClene, or just replace it with a new, old one (I had to do the same thing with my Plus -- tons of gunked up dust in there!).

power supply stability on the plus'? from personal experience, I've had mine on continuously for about 6-days with no power or overheating issues.

sad mac/happy mac, and flashing ... i have no idea.