I actually think this is a bad idea. Paris being Janeway's man a former Maquis who was captued but now a Starfleet officer was actually a good backstory and made him a complex character, as well as adding a bit of a Romeo X Juliette vibe to his relationship with Belanna as the "traitor" tension then went both ways in regards to him. Further, looking over your core cast, you've actually tilted things pretty heavily towards Maquis characters, with there being more of them than Starfleet while also mainly killing off Starfleet characters.Tom Paris/Nicholas Locarno: In my take on this show, they are one and the same person. Dishonorably discharged from Starfleet as a senior cadet, he was disowned by his father, a Starfleet admiral. He changed his name to put that past and the dishonor associated with it behind him, caught a transport to the outer colonies, and never looked back. He drifted for a few years, doing odd jobs that mostly revolved around running cargo and passengers between the colonies and to nearby stations. When the opportunity to join the Maquis arrived, he took it as fate and eagerly joined, offering his skills as an ace pilot. He ended up working for Hunapo, and will later become a helmsman for Voyager. As for why he and B'Elanna don't hook up while on Chakotay's ship, I'm thinking that they could've started out actually really not liking each other, even if he kind of had a crush on her. Or he found her too intimidating to approach. Or something. Anyway, eventually the crew will learn of his true identity, so that should be interesting.
I'd actually suggest going with the headcannon some people have regarding Paris/Locarno, that Locarno was an assumed name he used at the Academy to prevent any nepotism and/or avoid embarrassing his Starfleet Admiral father.
This means you don't have to worry about why Paris and Bellana didn't hook up, and can even use their relationship and how it's going as a proxy for how well the Starfleet and Maquis crew are getting along. Early on they are constantly at each other's throats, sniping at each other, etc., but gradually warm up together and their eventually marriage is the point where you know that the crews HAVE integrated, even if they still have differing opinions.