Bah! That's what Transformers: Rescue Bots is for
True. For the older kids (8+) in the end it is alien robots doing stuff to each other, not humans throwing down or bleeding. Scooby Doo has shown vampires biting humans and sucking their blood - this didn't even have a great deal of mech fluid spilled! Watch Generator Rex or Ben 10 - when fighting humans the humans just get knocked out, when fighting robots or aliens (and TF's are both) in both those cartoons the bad guys get ripped to shreds! I work at a school and while it is possible for an 8 year old to get freaked out by this, I think the vast majority wouldn't. It's a desensitized generation and everyone enjoys a good thrill/chill.
I quite liked this cartoon (once again loving Knock Out!). I like vampires but I LOVE zombies and this took a nice bit from each horror genre.
I was ambivalent to TFP ending as I wasn't a massive fan of season 2, but season 3 is shaping up that good I am lamenting it's demise. The writers are doing an awesome job here and entertainment abounds!