Depends completely on the drake... and having certain amounts of females may ease this but certain breeds, heck personalities play a role in this behaviour. My Pekin drake is a real pill, he has 5 ducks, my main call drake? he's sweet but i have some scovies that are nice boys some who are a tad over the top and i oodles of girls ... it's definitely not a once size fits all answer, that sadly is the trouble with it all lolLOL. You're starting to remind me of a parent whose teenage daughter is about to start dating. Maybe you could make them a little dimly-lit designated area and play some Percy Sledge music so they'd know that's where to go when they're in the mood to do stuff, but I agree the diapers could be an impediment. I keep forgetting about the diapers.
I've never personally had a drake that became agressive during mating season, but I know it can happen just from reading/talking with others about their experiences. It's most often related to too many drakes competing for the same ducks, but I'm sure there are other reasons I'm not remembering right now.
Yep, I completely agree with that. My personal feeling on it is that at least most animals prefer to have mates, but most will also do at least reasonably well without them, though there are some exceptions to that. My biggest concern in Amykin's situation, and it might be completely off-base, is that two ducks might be more likely to not get along with each other than having one of each. I think there's a possibility they would both see Amykins as their "mate" and compete for her attention, possibly to the point that they were agressive toward each other.
Again, though, I'm not saying that's inevitable. I have no personal experience with it and don't know anyone else who does, either. I just know some mammals display that behavior, but it might not be true of ducks, or it might vary with the ducks involved. This whole "duck in the house" thing is new to me, so I'm just trying to think of all the potential ins and outs.