On the maindeck, I think running less than 6 fetchlands is a mistake. I'd cut a Sea for it, if you want to keep the same number of lands. I like running 12 (w/o LED) but I think 11 is not enough--especially if you don't have LED.
I do find myself stalled on 1 land quite often with my current setup and certaintly wouldn't mind adding an additional land to the deck. This is especially true if I up the fetch base to 6 because I'll be thinning my deck more. From a generic list what card do you find yourself cutting to make room for the additional land? I wouldn't want to cut a threat but I could see going down to 3 cabal rituals.
As for the debate about bounce spells vs. Massacre I don't think that Jotun Grunt is a good enough reason to run bounce spells because when you are playing combo he isn't enough of a clock or enough disruption to be that much of a problem. As zeus mentioned the main problem cards are Mage and True Believer but bounce spells do have the added bonus of being able to hit chalice and null rod. For myself the artifact disruption has been less relevant than the creature disruption and this is why I'm running Massacre. What other matchups do you find yourself boarding in the bounce spells?