What a sweet story! And what a difficult assignment! Mike must fly faster than Superman, darting back and forth between Metropolis and Kansas for a good 18 years. It only makes sense that he's watching them both. That would explain their misteps; when he was off helping one of them, the other would land into federal disaster of his/her own making. How frustrating it must've been for him (along with satisfying).
I don't know how well Lois will do at assisting someone without getting any credit, but then again, she probably got used to that with Clark.
Beautiful story. I like how you fleshed out Mike's character.