Video editing software for pre-recorded lectures I am planning to record lectures. My lectures will be slides or notepad with voice-over. 

I am interested in a simple to use video editing software. The major things I need to do is


Cutting out a few seconds
Freezing the video for a few seconds
Speeding up or slowing down certain parts
perhaps do a completely different voice-over


The software should be as portable as possible though I am using Linux for the most part.
I have found Kdenlive to be a very good video-editing solution on Linux. It is free and open-source, with an active help forum and good documentation. It probably has many more features than you will ever need, but I didn't find the learning curve to be too high as a new user.