Just re-read this since it hit the archive. Great fun. As for why it took him three years, well I'm sure it was only a part time search.
Knowing Clark he first had to work through the "After all I let happen to her she'll never want to see me" blues.
Plus I am sure that everyone who hurt Lois, his parents, and the Daily Planet staff was made to really wish they had left her alone.
I can picture him working his way through the chain to grab amass evidence that would stand up in court.
Really dumb move on the part of Intergang.
So with wallowing in guilt, digging up the dirt and super rescues, he could only spend a small amount of time looking for Lois.
