IMHO SQLite is horrible format. using Matroska (.mkv) would be suitable for anything, vectors, bitmaps, audios and so on. It's essentially a container format like XML but for binary
Could you elaborate on what specific benefits using Matroska would have? One downside I can think of is that there are no programming environments (that I can think of) that ship a Matroska parser, whereas sqlite readers/writers are found in many standard libraries.
I thought about this (actually, an ISO based format like MPEG-4, but same idea). You could even represent edits as samples over time, and then play back the file as a movie!
WebM is based on mkv as well.