Backbone-Event: add array of models to collection

yes, backbone provides access to many underscore.js methods on models and collections, including an indexOf method on collections. it also provides an at method like you've shown.

var index = this.collection.indexOf(this.model);
var modelAbove = this.collection.at(index-1);

As @Paul noted, there is no predefined event fired before a reset. However, you can provide your own by overriding the reset method on your collection. For example,

var SVGCollection = Backbone.Collection.extend({
    reset: function(models, options) {
        options = options || {};

        if (!options.silent) {
            this.trigger('prereset', this, options);
        }

        Backbone.Collection.prototype.reset.call(this, models, options);
    }
});

And a sample usage

var c = new SVGCollection([
    {id: 1},
    {id: 2}
]);
c.on('prereset', function() {
    console.log(c.pluck('id'));
});
c.on('reset', function() {
    console.log(c.pluck('id'));
});
c.reset({id: 3});

See http://jsfiddle.net/nikoshr/8vV7Y/ for a demo

You could also trigger events on each model.