I would apply most of what you say to pre-marital heterosexual sex as well. Just as sinful by Christ's standards.
Not accurate actually. If we take, as orthodox Christians must, the Old and New Testaments as equally authoritative--clearly homosexual actions are sins of the most serious sort--punishable by stoning according to the Law which God gave ancient Israel. Fornication was very serioius too, but not always punishable by stoning....if adultery were not involved, couples would just be required to marry (Ex. 20:16). The incidents of homosexual behaviour however were punished by anihilation however, either directly by God (as with Sodom & Gommora (Genesis 18,19)), or by His people in mass (as with a group of militant homosexual rapists in Israel, slaughtered by their countrymen (Judges 19, 20)) or executed simply according to law (Lev. 20:16).
It is true the penalty for adultery was stoning as well... (wouldn't that do something for the divorce rate, eh?) The same was true for rape.
Christians often get confused, hearing the expression, "sin is sin after all!" which of course is not in the Bible, even in concept. Jesus spoke of sins with greater or lessor consequences (Mat. 18:6, Mark 9:42, Mat. 17:2) --and clearly for those not trusting in God's Savior--there will be greater or lessor degrees of punishment in hell--this is classical, conservative, accepted theology, amoung both Protestants and Catholics.
Any sin, no matter how small, has the profound consequence of death and just punishment--which if not borne by Christ--will forbid one entrance to eternal fellowship with God. However, in the Old Testament Law, and in the words of Christ, and the teachings of the New Testament epistles, its clear, some sins have much more serious consequences than others.
In Christian history--Jesus' attitude toward the adulterous woman ("Neither do I condemn you. Go and sin no more." (John 8:11)) has been reflected--in that where Church law held power, adultery has not been a capitol offense, as it was in old Hebrew Law.
Homosexual behavior though, is a different matter. Probably in light of God's treatment (final anihilation...after giving LOTS of mercy and time to repent...) of homosexually perverse Sodom, our ancestors made such deviance a very serious matter.