What is the meaning of ようで?

Question

I think ようで means "to look/look like", but I'm having trouble understanding it in the context of this sentence:

感動に水を差すようで悪いのだが、さっさと爾子に乗ってくれ。でなくば、城とともに潰れるぞ。

Also, is でなくば another form of でなければ?

Answer 1

• you de is the conjunctive form (連用形) of you da. It expresses that that something is similar (like) to something. It is in conjunctive form to connect the two phrases "kandou ni mizu wo sasu" and "warui". Compare with conclusive (終止形) you da in which "kandou ni mizu wo sasu you da" ([I] seem to be throwing cold water on the mood) would be a complete sentence leaving no room for "warui" (bad, [I] apologize for) to connect to.
• The expressions mizu wo sasu means ruin or interfere with a good thing, as in putting cold water into boiling water.
• Yes, de nakuba essentially means de nakereba. -ba is a conditional suffix meaning if. The former sounds older, but there is no significant difference in meaning.

Apparently something something happened and the speaker apologizes (warui) for indirectly ruining　(mizu wo sasu you de) the mood (kandou). I do not know the fuller context, but I interpret the sentence to mean something like:

Sorry to throw cold water on the mood, but hurry up and get on (ride) Niko. If you don't, you'll be crushed along with the castle.