First talk about translation.
"This is (a love) worth killing for" should be translated as 这是(一份)值得為之而杀戮的(爱).
為之而 = for
"一种爱" means "a kind of love". It is different from "a love" (一份爱)
Basically, your translation is quite accurate, but the problem with straight translation is -- "things get lost in translation". A common English expression may not be understood by many Chinese
The English idiom "at the end of one's rope" literally means "在繩索的末端". Which few if any Chinese could understand it base on the wording. However, the equivalent of this English idiom does exist in Chinese. And it is "窮途末路" (No more road; reaching an dead end). Both idiom metaphorically describe "being hopeless" ; "nowhere to turn"
A similar idiom is 走投無路 (nowhere to run)
For the same reason, I would rather interpret an English expression with a matching one in Chinese than translate the English expression word for word but doesn't express the metaphorical meaning clearly.
The line "a love worth killing for" in other words is "It is a love worth doing anything to have"
The same sentiment in Chinese would be "一份值得不擇手段去得到的愛" (a love worth having by hook or by crook) meaning you would do anything - including killing, to obtain this love
An idiom similar to 不擇手段 is 不惜一切 (not hesitate to give one's all)