The editor is actually WordPress, not PageLines, but because there are so many variables for shortcodes, they really should be customized on an individual basis for each person's site, rather than being made available through a button.
There's also a number of great options here, http://demo.pagelines.me/tools/, where you'll see the wide diversity of options available.
I have a question about this.
I am not sure I understand your reasoning for NOT including an editor interface for inserting shortcodes, including all their fine tuning etc.
I have seen this done extremely well in other themes. For instance, the ENFOLD theme available on themeforest has excellent shortcode implimentation. Shortcodes can be set up through an entirely GUI interface, via the Wordpress editor.
In the editor there is an Insert Shortcode button. Voila. Full access to highly complex shortcode entry.
So, with that in mind... what is preventing Pagelines for having a similar feature, as requested by the OP?