I have used Camtasia before to record my own gameplay videos (to share with friends, basically). I also have video-editing skills, I used to create a lot of videos before, even worked as a video-editor for a local news agency called "Liberty News" (Свободные Новости).
I can start off recording walkthroughs straight away for you, please contact me if you have any questions.
Best Regards,
Peter Sigaev.