For your movie I think that having gore is important because you want the terrorists to be frightening so by the way they kill their victims, that's how you'll make them scary.
im not too sure about this myself, i think for your film you might not want to be to overly graphic about it. Gore has, by all accounts, a set fanbase amongst horror fans and some will go see it just for that but it does tend to be used in story lines that are seemingly far fetched or have comedic elements to it. Hostel, Saw etc, Having blood filled terrorist themes might be a little to close to the bone for some, I personally wouldnt want to go there. But HeyHo this is the movies so anything goes i suppose.
When you release it ill look forward to it whatever you decide