I think raving lunatic is a bit much, but that's probably because I've actually dealt with literal lunatics over the years, both raving and not, so it takes quite a bit to really make that title stick in my mind. And I can't say I really blame you, I might've reacted much the same in your situation. In fact, I probably would have.
Like I said, just try to keep in mind that he really isn't Sylar. I've seen Gabriel spend hours devoting himself to recoding an entire security system so his friends wouldn't come to harm in the middle of the night. Hell, he saved my life, and the lives of most of the people here, a few weeks back and didn't even want to take credit for it. He is a good man.
And I guess this is where I should probably introduce myself so I don't start sounding like some rambling stranger.