What's so immature about wishing to have multiple ways to solve a quest? I echo the OP's suggestion: it would be nice to allow our own decisions to influence the outcome of some quests.

I would love to see things not be so linear for questing. If we make a bad decision, let's pay the price. We don't save Yuuki's hypothetical lady? Well, now the lady's husband charges us three times the amount he would otherwise.

No, I'm not suggesting that ideas like this are feasible all the time, but surely there can be a couple quests where we can be allowed to choose poorly.