#1 - Well yeah, but you're buying stuff when the books are hot and when everyone else is buying it. The key to speculation is guessing on future events, not to act on stuff that has already affected the price of the book, such as the announcement of a movie.
#2 - some of your books for sale, such as a SA Batman (can't remember the #), are mid-grade, not keys, and there's no reason for anyone to pay a premium on the book just because it is graded. I would be very surprised if you could sell that book for more than a raw one in the same condition. So that's $35 lost in grading fees or whatever it is.
#3 - This is why you shouldn't be making purchases for hundreds of dollars if you don't understand what you're buying. Start smaller with $40-$50 key issues, not $500+ books that can't be sold (such as those coverless JLA1s or whatever it was).