Brain-dump: Bzr and Bzr-Explorer with Launchpad account

Since it was more than a couple of weeks ago that I got bzr and Bzr-Explorer working on my old Acer laptop, as usual I forgot the salient steps, and spent the better part of half a day futzing around a new install, trying to get it to let me pull down the latest revisions (bzr pull) of Acire. 

So, here's a brain-dump for (sighh) the next time I have to get a bzr-based setup working with a Launchpad account:

• Bzr needs command-line init before you can go GUI: If you plan to upload code, or to pull/merge/update an existing branch on your computer, the first two bzr commands you should run in your new installation are:
  bzr whoami your_name_and_email_address   
  bzr launchpad-login your_launchpad_username
  where the info in the first command should ideally be your handle and a real email address, and in the second, the username for your Launchpad account.
  While Bzr-Explorer has a Settings > Credentials menu option, that only opens the bzr authentication.conf file in your chosen editor - and before I ran the two bzr commands above, the file simply did not exist. Apparently there's no way (yet) to do this initial config via Bzr-Explorer.
• New SSH key for a new hostname: I'd created my SSH key in Ubuntu 9.04 on my Dell laptop, whose hostname remained the Ubuntu-installer-default primary-username-laptop (in my case, "edgar-laptop"). So when I copied it across to my Karmic install on my Acer lappy, it worked - because once again, I accepted the default 'edgar-laptop' hostname. Duh.
  I was beginning to get a major crick in the neck, typing on the Dell keyboard but looking at the Acer screen, where Synergy was funneling my keystrokes - so I decided to create a Virtualbox VM with Karmic on my Dell, under Ubuntu 9.04. In a fit of appositeness, while installing 9.10 I chose a more relevant hostname - 'vm910'. Yay, me! :-/ Ha!
  I rsynced over a goodly bit of stuff from the Acer laptop into the VM, including apt's package cache (which did save a ton of time and bandwidth), and my SSH keys - forgetting that I had a different hostname in my VM :-(
  Long story short: for several attempts at pulling updates for an existing branch on my HDD, I kept getting public-key-access-denied errors.
  Fix 1: Moved the unusable SSH keys out of the way, generated new ones in the VM. Uploaded the new public key text to my Launchpad account's SSH keys page.
  Result 1: New error message "Agent admits it is unable to sign the request" (or words to that effect).
  Fix 2: Restarting Bzr-Explorer had no effect, I guessed probably it was the GNOME keyring that had the wrong key cached, or was heavily confused. Well, Winduhs-style... just reboot the VM! Heh heh...

This sorted out the issue; I could pull down the latest revision of Acire without issues.