I understand where you're coming from. In real life, if I was moving in, I'd probably enjoy a little surprise party like that. I suppose I should've elaborated on how it was odd that the same thing doesn't happen when cancelling other events involving guests, such as parties, weddings, or keyholder events. So why the welcome wagon specifically? Like I said, if not removing the relationship hit, maybe include an option in the options menu to disable it altogether? In terms of gameplay, I prefer to do things at my own pace, so I don't care much for forced events. For that same reason, I don't usually have my Sims hand out keys.
@The_Ratticator If I remember correctly in my last New Game I had my Sim travel to a different location-- a library to jump-start some of her skills-- before the neighbors showed up. When she returned home a few hours later there was no welcome party. I'll have to test this again to make sure it was not a glitch. I know this is not exactly what you are looking for but it might work, i.e. no welcome party and no negative relationship hit with the neighbors.
