Fridge Horror: When Lou realizes "Home Sweet Home" is playing as he is in the garage he really is getting down to it as if he's just happy the song is on... but later you realize he was planning on dying.
Another Fridge Horror: Nick, Adam, and to a lesser extent Jacob are all going to have no idea what they're lives have been like over the past twenty years. What if April mentions something about her and Nick's wedding? He's going to barely know her.
They could always ask Lou
Fridge Horror of the squicky kind when you watch the almost-threesome scene knowing that Jacob is Lou's son.
Fridge Logic: Lou uses his knowledge of the future to preempt Google and redefine Motley Crue with himself as lead singer. How? Knowing that Google exists doesn't mean he has the wherewithal to actually invent it. He's not a programmer and wouldn't know who he'd have to torture to get the vast amount of information he'd need. And how did he manage to get into Motley Crue? Prove he could predict the future and promise to make them rich(er)? Might work...
He wouldn't have to be a programmer to preempt Google. He'd have to have money to buy the biggest share in Google and cause a name change to suit him. He didn't have to invent it, just fund it.
Fridge Brilliance: Every time Lou is about to have sex with anyone other than Adam's sister, he is prevented in some way. First, Jacob refuses to do a Three-Way with him, the second time a squirrel runs onto the field of the NFL playoffs and changes the outcome of the game, thereby making Lou lose his bet (He would have received a "classy blowjob") All of this ensures that Jacob would have been born, since the semen that would have otherwise made Jacob would have been wasted.