yes I am aware of typical parmesan having rennet in it since I make it a point to read the ingredients of whatever I buy. But there are vegetarian version available in Health foods and I buy mine from Whole Foods. But will add in Vegetarian Parmesan for those who are not aware.
Actually this Pesto is with minimal oil and cheese. Pls refer to other classic recipes in the internet and you will know the difference (along with the original recipe from Giada where I provided the link). I doubt if the store bought version has less! Also this Pesto recipe serves 4-6 servings so its quite a lot. Modifying it to use less oil and cheese is your prerogative but it will surely affect the taste and wont taste like regular pesto. Usually I cut down little more oil if I am going to use the pesto imm. by adding cooking Pasta water to it.
I think you would have to freeze eggplant and pesto separately. I am not sure if together they would stand well. Warm it up and serve with freshly cooked pasta. Also I remember reading somewhere that while freezing Pesto it is better to omit the cheese since it does not freeze well and add in the cheese later while making the dish. Personally I haven't tried any of the above methods since I prepare this as and when I make it :)
Too much oil indeed. I found cutting the eggplant into small pieces and using 1 tbsp of oil along with salt more than enough to cook it well. And yes, covering the vessel too to create the steam. For the pesto- walnuts work v well too. I haven't personally tried with peanuts yet