The gore and blood isn't bad. I'm not one for even animated blood, but it's pretty minimal. It has the convenient habit of moving the screen away suddenly if there is a direct attack, though there are still a few parts I cover the screen on because I'm a wimp. I'm sure you can make it through, it's definitely worth it.
The doujinshi is even better after watching Yayoi's backstory episode. I don't know if there is one for Shion, but I hope so. I'm a little more than halfway through the series now.