"Civil partnerships/marriage are essentially the same thing legally"
But as I've tried to explain they're not. From how they begin (you can have religious content in a civil partnership ceremony) through to how they end (there's no explicit allowance for adultery to end a civil partnership) there are constant and slight legal differences between marriage and a civil partnership. The fact that there even has to be a separate piece of legislation is probably the biggest, most pointless and most offensive difference.
So they're not the same thing.
"I don't see how certain religions can be forced to conduct gay marriages"
I don't think anyone's saying that.
What seems to be being proposed is that gay people will be allowed a marriage in exactly the same way and on exactly the same terms as straight people. And that includes an allowance for Churches to deny a church wedding for what might appear to be biased or prejudiced reasons (begin divorced or being a woman who likes women's bottoms).
So stripping away a whole parallel set of pointless legislation that there's really no need for just because at the time they, as you correctly say, wanted to "avoid enraging traditionalists".
I mean really can you possibly understand why on earth we've had to come up with a completely new set of laws, terms and definitions when they could have just allowed gay couples to marry and the whole thing would have been dealt with.
This is just about treating people the same and applying the same laws to them.
Why should you be able to have a hymn in your civil ceremony if you're gay but not if you're straight?
Why should you be able to divorce your partner just because they've been unfaithful if you're straight but not if you're gay?
Why do we need a completely separate set of laws when one, correctly amended, will do the trick just fine?