Personally, I think that IDR is a waste of money. it doesn't save any time at all, does EXACTLY what you would do, and operates through a wizard. and if you cannot do a manual restore, why are you the one doing the restore in the first place?
Having said that
1) Yes, you would need one IDR license for each machine that you want to perform IDR on.
2) Backup as normal. Create a boot CD specific to the second machine, boot/rebuild from that, let it re-boot, then restore from last tape from the media server
3) As far as I know the answer is yes.