Adam Cuerden says, "I believe the VE team intends to have a some one click solutions in the near future, including adding templates of your choice to a bar? Although I'd hope there'd also be a few automatic lists you could choose to pull up - cleanup templates, etc."
So, it would be really comfy for users if the template editor, beyond being able to let them select what they need by typing the name, asked "Which kind of template do you want to add?" and provided lists of the most used/popular ones, divided per set (cleanup templates, citation templates and so on).
Or just a way to store one's most used choices.