I'm currently playing a Spider Blood Assassin in a campaign, and my brother mentioned something about Silk Weaver.

For Silk Weaver, there is no weight limit, that can lead to instances where a druid turns into a gorilla or some other heavy animal that can climb, and climb up the rope behind you, without the rope breaking. So, for the weight limit of the rope, it should be X + SBAs weight + SBAs max carrying capacity.