I want to answer these, but since I am at work, I don't have the liberty to write out as much as I want. I hope to get to this at home, if I remember!

But quickly, Hiro has now learnt from his dad what he should not do and that's why he's not doing what he did back in Season 1. Even if he's jumping back and forth hearing things and trying to stop what's gonna happen. Since it hasn't happened yet he has a bit of leeway. ;)