Huh??? We don't claim all of what to be true? And demonize Jesus?? ^o) I have no clue what you're talking about.
**UPDATE** Ok, now I know what you're referring to. I think you don't realize what you've read. It is NOT Islam portraying Jesus, pbuh, in this light. Those verses are from your Bible, NOT the Qur'an. I'm afraid you'll have to discuss that with the biblical scholars. In Islam we hold Jesus, pbuh, and all the chosen Prophets of God in the highest esteem. As Muslims we love and revere Prophet Jesus, pbuh and would never say such things. So, why the biblical writers would say something so vile is beyond my comprehension.
As far as whether or not that site is reliable, I can't make that call as it's not a site I use for resource or research. My point is that it is responding to an Islam hate site and it would be better for you to learn the basics of the Islamic faith before you jump in trying to understand points being refuted.
Peace,
Hana