At the end of the Option 1's thread, somebody is having similar issues as you (not prompting to plug in the device). Starting at post #84 (and even just a few weeks ago...so it's fairly recent): How to root kindle fire any version (including 8.4.6) - Page 9 - xda-developers
They apparently ended up using this guide (and they're on 8.4.8), and got it to work: [ROOT][HOW TO] Root the Kindle Fire HD and 2 with Windows - Noob (Simple) Version - xda-developers
Which was option 2... guess you shoulda just stuck with your first choice from a few posts above and went with Option 2 to try and root . Sorry... my bad about that.
They apparently ended up using this guide (and they're on 8.4.8), and got it to work: [ROOT][HOW TO] Root the Kindle Fire HD and 2 with Windows - Noob (Simple) Version - xda-developers
Which was option 2... guess you shoulda just stuck with your first choice from a few posts above and went with Option 2 to try and root . Sorry... my bad about that.