
FamiliarMask |

It doesn't specify the hands required. On the one hand (so to speak) it's a thrown weapon which is usually (not always) 1H, on the other it says it's like a meteor hammer which is a 2H weapon.
Maybe someone knows something about the RL weapon it's based on and could say?
In game terms, based on real world use, it should definitely be a two-handed weapon. Realistically, it'd be more accurate to say you use your whole body to control it, as techniques tend to involve wrapping it around your arms, legs and neck to control and redirect the dart.
The rope dart and other similar weapons aren't represented very well mechanically in Pathfinder, IMO. I'm not sure what the RAW is on hands needed, but I wouldn't allow using them for two-weapon fighting in my game.
Here's a good video of a guy doing target practice with one that has nice slow motion shots...
https://www.youtube.com/watch?v=UShagbf79J4

ErichAD |

Legally there are no problems with it. I think it's realistic to allow a character to use one rope dart and treat it as two for the purpose of dual wielding since in normal use you're directing it with any number of limbs. Use your free action recovery to place it in your other hand and go to town.
It's a little similar to the battle poi which are two weapons treated as one for some purposes that also grant two weapon fighting when proficient with them.