As a loyal Catholic, (which is very similar to Christian,) I can assure you that there is no place in the bible where it says that killing gay people is ok. I couldn't have worded it better than you did.
And the line "A man shall not sleep with another man as he would a woman" ACTUALLY says "A man shall not sleep with a boy (child) as he would a woman."
The reason this came to be was because back in the middle ages, all the Bibles were in Latin, and only the priests knew Latin. So, the people who attended mass had to believe everything the priests said, as they were the translators. One priest decided that he didn't like people who weren't straight, and changed that line. Martin Luther had it right.