Many years too late, but if you're still around (or any future reader) I recommend giving GridPlayer a try, here is the description:
Simple VLC-based media player that can play multiple videos at the same time. You can play as many videos as you like, the only limit is your hardware. It supports all video formats that VLC supports (which is all of them). ...
A somewhat less user friendly but possible more powerful option is MoviePy which is a Python wrapper around the command line FFMPEG it downloads and installs FFMPEG on first use - when used from within iPython it can be a pleasure to use and can do most of the things that you mention.
cut a video, You just need to know the point(s) in time that you want to ...
That looks more like the job for a 3D modelling and animation suit, though some more advanced video editors may be able to do it to some extent.
There are many payed and free creation suites that may do that, most are commercial software, others open source.
AutoDesk 3D Studo Max
Blender is free and open source, we have a community ...