Hate me if you will, but I highkey ship Connie and Rodney.
1. Redemption Arcs
I've always had a weakness for redemption arcs, and I feel like Rodney coming back into the series as a Christian would be a very good way to exemplify God's willingness to take "bad" people and make them into something good. And, since Connie has seen how bad he was, it might help her to be more willing to pray for people like her dad, who aren't Christians, so that they might have a turn around as well. Besides, for some reason, Adventures in Odyssey writers seem to like to make characters be very black or white morally. With the exception of Buck Oliver, who was obviously good from the start, there is always a clear line between "good" people and "bad" people. Honestly, it'd be nice to see a more realistic change.
2. Jules's need of a father figure
Hear me out on this one: Jules really needs a father figure in her life. Now, I realize that Rodney is not the best candidate for that, but if he comes to Christ, and does change, I feel that he'd do okay. Connie is already kind of Jules's mother figure, but one parent isn't enough. (God being analogous to a father is different. He's God, he can literally do anything he wants.) In fact, kids who live in a home without a father figure are more likely to become criminals. Another bonus of Rodney kinda being her father figure would be that he would've gone through that exceptionally rebellious teenager phase, and could help Jules make the right decisions by explaining the consequences in such a way that Connie couldn't.
3. I just feel like it'd be nice to hear Connie NOT fawn over her significant other
I don't like the mushy stuff, and I can assure you, that if Connie and Rodney were a thing, we wouldn't hear any really mushy, ooshy-gooshy stuff, and instead hear things that actually sound like a healthy relationship: like honest compliments, and respectful comments, maybe even a few pranks! Healthy relationships aren't built on flattery and infatuation. They're built on mutual respect and a desire to do life together. And none of the relationships that Connie was in previously had that.
Please, just consider this. It's only my opinion, of course, and you don't have to accept it or whatever.
What an interesting ship. I don't know if I've heard this one (seriously) suggested before and can kind of see it now that you've explained. Honestly, one of the things I like best about it is that the same voice actor who played Mitch also voices Rodney, so I would be able to pretend that it's a deep undercover act and it's really Connie and Mitch getting together.
Around the time Mr. Edmiston died, I wondered how they were going to resolve it in the series. In my head I pictured a potential story arc where Tom and Bart were both on a train for some reason. There would be some sort of catastrophe and both of them would die, probably with Bart having some sort of deathbed conversion (it might not be realistic but, AIO and "happy" endings). After that, there'd be episodes exploring Rodney and his reactions in the aftermath, now that his "pop" is gone. Of course, nothing remotely like this ever happened, but I still think it was an interesting idea. Maybe something like this would have been a good way to shake things up. It doesn't look like AIO has any intention of ever revisiting the Rathbones, though, so I guess it's water under the bridge now.
I do think your relationship concept is a good one, with impeccable reasoning, though I admit I have a hard time imagining a "Connie Rathbone".