くれてやっかい is a contraction of くれてやるかい. The word 厄介 is not related.
In general, るか may contact to っか in very informal speech:
するか → すっか
やるか → やっか
見るか → 見っか
なるか → なっか
来るか → くっか
生きるか → 生きっか, 食べるか → 食べっか, ...
すっか/やっか are relatively common, but others are uncommon. I probably have not heard 乗っか, 寄っか, 切っか, 取っか, 怒っか and so on, so this works with only a few common ...
Yes, the second じゃない is an informal way to say something like "right?" or "don't you agree?". You can see the rest of the sentence as the actual statement, and じゃない just as a way to involve the other person. Something like "isn't it?", if you want to have a negative example.