1) They usually mean that it is written in the bible.
2) As another answer wrote, you provide no reference. It is Lev 18:22. I have to admit - without even researching - that I consider the various English translation provided by dozens of well-respected scholars who were responsible for the many versions that I have read far more authoritative than yours. I do not recognize your translation in any verse of any English version, including the JPS Tanakh http://www.jewishvirtuallibrary.org/jsource/Bible/Leviticus18.html . Perhaps you consider your skill superior to the (mostly well-respected) ancient language scholars, both Jewish and non-Jewish professors, who have provided English translations for us to date, long after 1607, using modern scholarship (not a 1607 translation).
Here are some of the bible verses that specifically condemn homosexuality, or at least individual types of homosexual acts, with a brief overview of the literal meaning from the original language (source: http://www.religioustolerance.org/hom_bibl.htm )
Lev 18:22 (Moses, specifically against homosexual anal intercourse, despite your self-proclaimed "correct" translation)
Lev 20:13 (Moses, general condemnation of male homosexual sex)
Deu 23:17 (Moses, probably specifically against male homosexual temple prostitution)
Rom 1:26-27 (Paul, although vague in some respects in this verse, is definitely condemning, at the very least, lesbian and homosexual acts under specific circumstances. Some claim that this verse refers only to temple rituals, but neither temples nor religious rituals are mentioned in these verses)
1Co 6:9 (Paul, specifically against male homosexual acts)
1Ti 1:9-10 (Paul, although the translation is not fully understood, is at the very least condemning some specific type of male homosexual act, if not male homosexuality in general)
"Or simply let you heart witness to you. Why would God create a unique person and then condemn that person for being unique?"
He wouldn't, of course. Even if you have put your faith in the (scientifically unproven) theory that homosexuals are born with homosexual attraction, homosexuals are *not* born performing homosexual acts. For most men, desire for beautiful women (not just a wife) is "natural". We can see clearly from reading Paul that it is the act of fornication, not the desire, that is sin.
"Paul's words just about completely negated everything Jesus actually taught."
This is a verifiably erroneous statement. It makes me look on your translation with quite a bit more skepticism. There is no contradiction in Paul's letters with Jesus' teachings - if you actually read them and consider the context.
1) Moses *did* come to this conclusion, after God told him specifically (in Lev 20:13)
2) It is fallacious to claim that Jesus never came to that conclusion. Since we have no definite recording of Jesus' teaching in this matter, we can only say with authority that we do not know what Jesus said specifically concerning this. However, considering Jesus' adherence to the spirit of the Mosaic Law, it is clear what his teaching on this would be, at least in regards to male homosexuality.
3) Paul definitely came to that conclusion - or, alternately, was regurgitating the teachings of Jesus.
Thus, we can clearly see that the bible *does* condemn, at the very least, specific types of homosexuality (both male and female). We can also see that the bible specifically condemns male homosexuality in general. Finally, we can see that in no place is the bible permissive of homosexual acts of any sort. Thus, it is plain that homosexual acts, in general, are opposed and condemned by the bible.