How do non-violent Muslims explain the violent verses of the Koran?

For context: I am not a Muslim. In the wake of the most recent terrorist attacks in Paris, I would like once again to ask the question: "Does Islam promote violence?" I realize this question has been asked before, but I have a specific way of asking it: It seems obvious that it's false to say Islam DOES promote violence in ALL self-proclaimed Muslims. It seems equally false to say that Islam DOES NOT promote violence in ALL self-proclaimed Muslims. When people who call themselves Muslim kill innocent people while shouting words from the Koran and in the name of Allah, it's pretty clear that for THESE people, their beliefs in Islam promote and result in violence. Now whether or not their interpretation of the Koran is "correct", or if they are "true" Muslims, well that's another question. That is the question I'm trying to answer today by understanding how non-violent Muslims interpret the violent parts of the Koran. For example, there are many troubling versus in the Koran that do, in fact, seem to promote violence, especially against non-believers. How do non-violent Muslims explain these verses? Is it an issue of translation? Is it an issue of cherry-picking which parts of the Koran to follow and which to exclude? For example, the Bible clearly states that being gay is a sin. However, there are many Christians who welcome the gay community into the church and will even perform marriage for these couples. This is a contradiction that requires thought to reconcile. So, how do "true" non-violent Muslims reconcile these contradictions regarding the violent verses of the Koran? Here are some examples: > Quran (3:56) - "As to those who reject faith, I will punish them with > terrible agony in this world and in the Hereafter, nor will they have > anyone to help." > > Quran (8:12) - "I will cast terror into the hearts of those who > disbelieve. Therefore strike off their heads and strike off every > fingertip of them" > > Quran (9:5) - "So when the sacred months have passed away, then slay > the idolaters wherever you find them, and take them captive and > besiege them and lie in wait for them in every ambush, then if they > repent and keep up prayer and pay the poor-rate, leave their way free > to them." > > Quran (9:29) - "Fight those who believe not in Allah nor the Last Day, > nor hold that forbidden which hath been forbidden by Allah and His > Messenger, nor acknowledge the religion of Truth, (even if they are) > of the People of the Book, until they pay the Jizya with willing > submission, and feel themselves subdued." > > Quran (9:73) - "O Prophet! strive hard against the unbelievers and the > hypocrites and be unyielding to them; and their abode is hell, and > evil is the destination." > > Quran (17:16) - "And when We wish to destroy a town, We send Our > commandment to the people of it who lead easy lives, but they > transgress therein; thus the word proves true against it, so We > destroy it with utter destruction."