Your project sounds interesting and I'm eager to give it a try. One question though: why don't you provide your "orm" functionality by extending Backbone's Model/Collection classes instead of "mixing" in these functions via initialize? I'm thinking of something like:
Pokepic.Model = Backbone.Model.extend({
hasMany: {},
embedsMany:{},
_setupRelations: (){
//all inner relations are setup here
}
});
The user would then simply use your Pokepic.Model / Pokepic.Collection to specify his tasks.