It all will be fine-tuned as the game develops. If I'm not mistaken it's the main quest that may bother you. In sandbox mode, it will be disabled.Ok game.
However, failing to do some task should not end in a game over.
And there are 2 more possibilities to fail, run into debt and get room tidiness to 0. Everything else is non-threatening. With debt, I'll think about some event that will get you out of it, and I'll think about tidiness, but there are a lot of warnings to prevent that,