1. Downloading the thing in the FAQ isn't a magical fix, you're supposed to use to get a debug log and then show it to me.
2. If the drive can't read the disc, no wonder it was taking a while. You probably had a crappy burn - are you using decent media? Try burning at 8x or 12x instead of max (if that's what you're doing).
3. If you system gets hung up then it gets hung up. ImgBurn is not in control once the command has been sent to the drive and if if never gets a response it doesn't have the ability to abort anything.
On bootup your machine does lots of stuff, once it's finished it'll idle again.