While that's definitely not a bad idea, I think I would feel better if I did a completely fresh install, erasing everything on the HDD right now, even though it will be more painful. As for your questions, none of those things should cause a problem as my dad's 2009 MBP boots up quite fast, almost completely bypassing this blue screen altogether. Now, its reinstalling time.
Yes, but your dad's comp has a different account, so although it shouldn't make a difference, it could (especially if you are auto-mounting something like a folder or drive). I asked this as it may be a clue as to the cause of your problem, such as a faulty BT or airport module that is interfering with the boot process. You never said that there was another Mac (or Apple product) in the house, so I was just starting at the basics and trying to help with a new product,as you made it sound like this was your first Mac and trip to the other side. Have fun with your install.