I myself don't really see a need for an AGI lib. For one, there are more than enough random AGI tools out there, far more than enough--very few of which spark more game creation, or are even used, even really good ones like Noptec Vector. Most people who couldn't write an AGI resource loader wouldn't be able to do much with the loaded resources anyways, heh. Secondly, there really isn't much to AGI resources, I know their formats virtually all off the top of my head, and have whipped my own loaders/savers a number of times in mere hours.
What I think was really needed were simply the Sound Editor, Picture Editor, and your other top notch tools. The compiler could be improved, but works very well as it is. The resource handling could be improved, but works fine as well. The picture and sound tools on the other hand had been lacking, and the work you've done to fix that is fantastic! I think the best thing is just to get those two tools to a 100% state.