I foolishly created this blog, super naptastic, using my Comcast email address, not realizing (a) how blogger is now a Google thing, and (b) I already created a blog under blogger / blogspot / google using my Gmail email address. (“Dire Bends, or the definition of impossible,” a great concept I never did anything with.)
Here’s what I’m wondering: Can I somehow transfer “ownership” of Super Naptastic to my Gmail and Blogger account without losing all my great content? Or do I need to keep logging out and logging back in with a different account every time I want to post?
I don't know if you can actually transfer ownership, but you can make your other (Gmail) account a contributor on your blog, and then just start posting with that profile and forget that the other one is even associated with it.
Go to the "Settings" for your blog, and on the "Permissions" tab click "Add Author" and enter the email address that you would prefer to post with. After you've added yourself, you can grant yourself "admin" privileges, which will allow you to do everything with the other login that you do with your Comcast one.
(You might even be able, after you've gone that far, to log in with your Gmail account and then revoke the Comcast account's privileges… Not entirely sure about that, though)