I do agree that he is off his rocker a bit when it comes to Christianity and his video on Scientology is idiotic.
I'm Catholic and follow the "Let he who is without sin cast the first stone" philosophy. If you aren't hurting me, anyone else, or trying to push your beliefs onto people who have declined your offer, then I really don't have a problem. I may think you are weird, sick, whatever, as is my right. Just leave me out of it. One of my best friends is a Jehovah Witness, another is gay, a co-worker/friend practices Sikhism, (Very interesting religion to read about BTW.) quite a few I have no idea what their religion is. Each of us does our own thing and doesn't push our beliefs onto the other.
The problem I see with his videos at times is that he tends to group the entire religion into one unit. With Christianity you simply cannot do that as there are so many sects and variations of Christianity. It think he wouldn't look so nutty if he separated groups of a particular religion where appropriate. I sure as hell wasn't celebrating abortion clinic bombings and such when they happened. I was pissed as hell about the priest sex scandals. Don't group me in with those idiots.
Sometimes it is appropriate to group an entire religion. As we can see from observation, Islam is more or less one homogeneous religion with people who sometimes take differing interpretations, unlike Christianity where there are completely different schools of thought. Christianity certainly doesn't behave like a large angry mob like Islam does. In his videos he correctly separates the Islam extremists (Sadly, who seem to be a majority) from the moderates (Who unfortunately keep quiet most of the time.) who just want to be left alone.
He is human and even though misses the mark some of time. His thoughts of Islam are shared by many people and much of what he says is true.