It would be interesting if you could marry multiple candidates at a time. I would be very curious to see if you could have all the marriable people working on your farm at the same time.
I'd much sooner vote for a mod that expanded on the already present marriage system. I could imagine a way to be able to influence my partner to do... certain things. It would be cool to take him with me on a trip, or at least tell him what to assist with on the farm. Like "Could you please water the crops tomorrow morning?" and he'd decide to help based on what your relationship has been like lately... IDK