Between these two, starting a new game and resuming a game, for me most difficult is starting a new game. Resuming is no problem. I now have 2 saved games that I alternate between but starting a new save can be a chore for me because before I play I HAVE TO put down community lots that I prefer to use and that can take some quite a long time especially in Newcrest. That is mostly due to my problem with attention span and the impatience that comes with it. I am seriously considering creating a save game ready with all the community and residential housings that I like to have and add to each new saved game. That way I can just start a new game without the fuss that comes with it.
But my lack of attention span these days is the main cause that the only saves that I can really concentrate on is my very old one from 2018 and my newer one I started...Either beginning this year or end of last year and of course I rotate with gazillion households in both. The reason my second saved game has so far helded my attention is because I have been seeding that game with my 'own Sims' (mostly townie saving and households that the game has moved in into unoccupied houses). These Sims, I give a past, present and a sketchy future that is malleable. If I manage to create a household that I like and is interesting to me, they are a keeper and I find it can concentrate better on them.
That being said, I have no compunction over killing Sims. If Sim is uninteresting or is in the way they will meet Mr. or Miss/Mrs Death. If a Sim dies accidentally I won't have any Sims interfere on their behalf. I HAVE had Sims beg for mercy for their friend/lover/family member of course especially if I find it is not their time but...if I have a eureka moment when they flop onto the floor and discover that their death might give off some good storytelling or a changes I had not foreseen before, then my remaining Sims will get a nice urn on the mantelpiece.