Sorry for not arguing against this well-thought argument.
In the Crusades, various parties tried to take control of the Holy Lands in the names of their Gods. In South Thailand, the insurgency happened because fundamentalist Muslims wanted control of the region to establish a Islamic state independent from Thailand. Part of the Israel-Palestine conflict involves control over Jerusalem.
As I mentioned before, there isn't a single-agreed version of the Word of God throughout the world, so to one branch of, say, Christianity, there are a load of Christians out there who are "doing it wrong". A religion isn't just defined by what is in their religious texts - it's how people apply it, too. If people believe they are committing some act in the name of God, that is faith too. No, it might not reconcile with the teachings of a certain one of many branches of Christianity, but I genuinely don't think this matters. What matters is that the person believes he or she is performing something that is correct to his or her faith.
Certainly, it is an argument for banning extremist interpretations of religions. However, this implies there are non-extremist interpretations of religions and I would like to know what those are. However, I don't think violence against other religions and intolerance towards homosexuals (amongst many other things) should be in these religious texts - and if I were religious, I would be committing blasphemy right now.
Many of us have certain beliefs, and we may have had beliefs as a child that have been lost over time for the right reasons. We might have believed it was right to bully the weak as a child, but we eventually grew up and realised it was wrong. Some of those beliefs are religious, some of those are moral, adapted from our peers and relatives.
Religious beliefs, however, cannot be questioned - you can't question the Word of God. Other beliefs, however, can be questioned when we have evidence to suggest it's wrong - we realise that it is wrong to bully the weak since it hurts others and it's not nice when it happens to you - the belief that bullying is correct is now wrong.
This is where it hurts others the most - because your religious beliefs cannot be questioned. Your parents won't question them. Your religious peers won't. It quite frankly can't be believed to be wrong. It's impossible for opposing religious views to find a compromise - if you do, you're twisting the very words of your beliefs and are no better than those who twist their words to suit their agenda.
I think it's good to have some beliefs as a moral code for yourself to follow. Those beliefs will hopefully help human society, so those beliefs will be good ones (i.e. help the elderly, be nice to others, treat your partner with respect, etc. etc.). Maybe some of those beliefs had good intentions but it turns out that future society doesn't accept them - you will have to adapt those beliefs. That shouldn't be wrong. I'm just not convinced religion follows this mindset of being able to adapt.
Religion was good for society in the past; but we have a better framework for society now, one that doesn't assume that some religious book written thousands of years ago and translated wrongly many times is correct, for the reason that it is more flexible.