How can I edit an Offline Recording (.flv)?

You have a couple of options.  You can convert these to a format you can edit together such as an .avi, as a test I first I grabbed a piece of software to convert the video from .flv to .avi
(I used the trial version of this, but pretty cool at $29 for the full version)
Then I could the free Windows Movie Maker software with my copy of Vista to edit the files.  Any video editing tool should work though.
Finally, if I wanted the movie (the ‘flat’ recording) back on my computer then convert it back to .flv using something like ‘Snosh’ (a $50 tool I use all of the time for video conversion) http://www.snosh.net/ or ‘Any Video Converter’ (free and an excellent conversion tool) http://www.any-video-converter.com/products/for_video_free/
Alternately you can use a specifically made .flv editing tool, I quickly hunted down this one and it worked incredibly well:
Then you can upload the joined file to your Connect Account (Content section).
IMPORTANT NOTE – Please note that you should ensure all of your virus protection and internet security software is up to date before installing any software.  Although GetConnect has used the software solutions mentioned above without issue, we cannot guarantee that the software solutions are free of malicious programs or that they will work flawlessly in your infrastructure.
Please perform due diligence on any software you download or use and follow your own company guidelines.