Yes.. The jutsu comes from his eyes not his hands.. Once mastered, hand signs are not needed.
Hahaha!!!! I hope you're joking.
Sure there exist some Rinn jutsu that can be use without hand sign but this two types of Jutsu sure using/need a hand sigh to perform(both hands).
The hand clapping sign is needed action to started the gravity attracting mechanism. Look at the scans I showed here.
I only believe your word if you are Kishi or some CT jutsu happen to be perform without hand sign in manga.
Even someone as experienced as Madara still need a hand clapping.
And tried to used a situations where Sasuke using one hand to perform a jutsu was just a weak reasoning. Those jutsus were not a Rinnegan tech.