Forced story progression would pretty much make me quit the game because it is completely counter to my playstyle. I would not go in and delete random marriages and children, I would quit playing. It's not something I want in the game. If it were a toggle option, I would never choose it.
I play rotationally with a bunch of households. I basically "play the town". I have a whole way in which I manage story progression in my game and it's part of the fun for me. In TS3, I had to play with one household and one world so I was constantly getting bored and abandoning saves. I like the way that TS4 lets me play now.
Do I want to see more hobbies and activities in the game? Yeah. Do I want to see townies enjoying themselves around town? Yeah. I do some match-making of unplayed sims on my own, but mostly, I have a growing group of playable households that form the main part of the town for me. I want to play those out and see what happens. As for other unplayed households? I manage those myself. I've been known to randomly marry off some townies and to create their kids. Sometimes I go back in later and make those households playable.
Anyway, I agree with whoever said there's no need to add "forced story progression" because you can do all of that in Manage Households and in the settings. Just marry some unplayed households to each other, create whatever children you want them to have with genetics (or go totally random and have them adopt) then move them into an unplayed house in the town. Turn aging on for unplayed households and they will age alongside your sims.
