First, you say you’re okay with noncommercial aggregators using your feed “as long as they ask my permission first.” Isn’t the whole point of the cc license you’ve chose that they don’t need to ask your permission first?

Second, if I understand your second paragraph, you are suggesting that, as a general matter, the appropriate cc license depends on whether the work that is to be licensed is commercial or non-commercial. That may be true for you (and hey, you can use any license you choose, or even go “all rights reserved”–it’s your work!), but I don’t think it’s true across the board. Examples of non-commercial authors who license their work for commercial and non-commercial work: authors of free software such as the software that powers our blogs. Examples of commercial authors who license their work for non-commercial uses only: textbook authors who authorize photocopying for classroom use only. Again, it’s fine for you to say that you are licensing your work non-commercially because you wrote it for non-commercial purposes, because you’re the author and all that really matters is whether your license makes sense to you. But I don’t see why your approach is a principle that should apply more generally.