‘But same sex sexual relations is a sin, as is lying, greed, gluttony, etc — no more or less worse than any other sin —’
Wrong! Taking a piece of candy without asking is a sin, disobeying your mother is a sin. Both are significantly less important than rape, murder, and sodomy. Sodomy is one of the most significant sins, possibly only overshadowed by murder. Murder destroys God’s creation, life. Sodomy openly mocks God’s creation, heterosexual procreation.
There are certainly degrees of sin. Not all sins are equal.
Unrepentant sin of any type is enough to get one into Hell. In that sense, sin is equal, but you’re exactly right. In this world, the results of sin vary greatly and deserve to be treated as such. Society would fall apart if it didn’t address murder, for example, but it can probably survive liars (although the latter deserve scorn).