Why would you want the resulting video file to be 3000x3000? How do you intend to play that back?
Any video file can be converted to a TIF sequence.
You would skip where you had to erase and adjust things by editing the video in an NLE like Adobe Premiere Pro.
As far as option B goes, I would suggest using several different stages of your painting and revealing them bit by bit rather than just trying to do the whole thing at once.
You've seen people draw on live video? That would be done with a
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