what bout After effects did ever use it in your work DE?
Nope, no After Effects. I pretty much just used the tools I've mentioned.
ADM, I can't PM you back cos I've got too many, but here's what I'd do:
Use VirtualDub-MPEG2 to open the .m2v, then select in and out points on the timeline and go to File->Save image sequence. Edit the frames then drag the first one back into VirtualDub, which will load the sequence. Then you can save as an AVI.
(As an aside, you might want to try writing an AviSynth script to load a .d2v file, which is an index file to a .m2v that you create with DGindex. Opening that in VirtualDub decodes the MPEG2 is a slightly nicer way, but the difference is barely noticeable).
DE