Those new peelers make peeling them a breeze. Before I used to have to slice them and then peel each slice with a paring knife.
It didn't seem to matter with my hummus, and I'm sure I must have gotten a female in heat for that. I have a version of your recipe without the garbanzo beans. I don't know if I'm game to try it or not.
Sometime I would like to roast a variety of veggies and include eggplant though. That Italian parma stuff never sounded too great. Maybe I would like it now because I do change about things.
There are versions of Baba Ghanoush that include Tahini, and come out more like hummus:
http://www.finecooking.com/recipes/baba_ghanouj.aspx
-JT