Yea, I wouldn't call them big either, but they happen none-the-less. For package developers it can be vital. Sometimes A must be loaded for B. It's mainly a third party javascript issue. The compatibility folder sometimes does the trick, but by contrast the same utility doesn't exist for package developers. It's a larger dependancy management issue not tackled by the current packaging system.

Yeah, the current packaging system is more of a download installer and less of a dependency management system. That should get a lot better in 1.0. As for Jade, https://atmosphere.meteor.com/package/jade-handlebars is working towards this. It also appears that Meteor is (or was) thinking of integrating Jade support in Meteor directly: https://github.com/meteor/meteor/tree/jade