Avenue Q/WMG

Rod doesn't actually have a girlfriend in Canada
I mean, think about it. We never see her, none of the characters save Rod have ever met her or spoken to her, and at one point, he gets her name wrong. I think he may be totally making that up.
 * Just maybe... I'm not sure... That's a pretty outlandish idea.
 * This is the most enlightening WMG I have ever read.
 * Of course nobody else has ever seen her, she lives IN CANADA. This WMG is totally implausible.
 * Why would he make her up? Are you implying that he is homosexual?
 * Idk, I mean, she would have met the other characters when she was there last week, but she had the flu. She had to stay in bed!

Kate and Trekkie Monster are related
Kate's just in denial. Seriously, would you admit that you were related to Trekkie?

Nicky is the Chessmaster
He has been controlling everything from the start.
 * He lowered the rent costs in avenue q by being lazy and leaving rubbish everywhere. This is why he developed a reputation for being messy. This made it a popular area for out of work people and, essentially, ex-students. Knowing the approximate age of students leaving college he left coins with their likely year of birth lying on the street in order to provide inspiration. This provided him with Princeton, a likely candidate for going out with Kate, and who he guessed would give the dime to. Despite knowing that Rod was gay he didn't share the knowledge until the group was gathered, hoping to cause a crisis, driving Princeton to dump Kate. He also knew that this would get him kicked out of Rods apartment. Once on the street he convinced Princeton that helping others was more satisfying than helping yourself, meaning that he started collecting the money for the monster school. He therefore created the monster school. Kate, depressed dropped the dime on Lucy which, as he had planned, caused her to convert to Christianity. He also contacted Ricky, because he knew that his manipulation would eventually convince Rod to come out, and that he would focus his attention on someone similar to him. He also showed the ex-child star that he lived to be laughed at, and this fulfilled him. Nicky is all powerful, and we can only be thankful that he is also a force for good.

It really was a lucky penny
After Princeton finds the penny, things go well for him: he feels good about his future, he starts to make friends, he gets together with Kate. After he gives the penny away, things start to go wrong: he starts to worry about his future again, he breaks up with Kate, he isolates himself from his new friends, and ends up with Lucy. Then the penny nearly kills Lucy, with million-to-one odds that it would hit her after being dropped. I call that lucky, especially since it starts Princeton on the road back to Kate and happiness!

Christmas Eve is Trekkie Monster's therapist
In the song "It Sucks To Be Me" Christmas Eve sings about her job as a therapist, but she has no clients. Conclusively, in the song "School For Monsters" Trekkie sings about how he has a therapist because of his trouble in school. Rod recommended Christmas to Trekkie, and voila!

Rod is also based on Drew Pickles from Rugrats
That's why he's a nerdy investment banker who's in the closet.