With the Mechadendrite Use (Weapon/Utility) talents, I read it as "In order to use any Mechadendrite weapon, you need MU(Weapon)". So to use the attack from the Utility/Medicae/Manipulator Mechadendrites as a weapon, you need the Weapon version of Mechadendrite Use.

However when reading through a thread that involved Mechadendrite Use (it was something about wanting other weapons as dendrites and twinlinking them) I got the impression from the posts that the only benefit from Mechadendrite Use (Weapon) was the ability to use the Balistic Mechadendrite, which implied that you are able to use the attacks from the non-Ballistic Mechadendrites with only Mechadendrite Use (Utility).

I'm now somewhat confused about what exactly you are and aren't able to utilise (having all of the Mechadendrites) but only having one of the Mechadendrite Use talents.

Some clarification on the RAW would be great thanks. (Though if you use some homebrew/houserule in relation to this I'd be interested to read it and possibly propose it to my GM)