u/Equivalent_War_1813

Kaneki use a large kagune to attack Arima/Eto, they get impress, and it ends with them jabbing his eye.

Kaneki manage to impress both Arima and Eto in battle which ends with them jabbing his eye. Since their intention is to groom Kaneki into becoming the one eye king its symbolic that Arima stabs his right eye (human) while Eto licks his left eye (ghoul).

Kaneki associates Rize with his ghoul side. Throughout the series Kaneki is shown to adopt several characteristic; their ticks, worldview, and fashion sense, from the human and ghouls that he meets. One of Rize's most notable haracteristic is that she is a femme fatale which means in this case Kaneki wearing a gimp suit himself isn't trying to be sexual he is trying to evoke Rize in his own way.

The best part of all of this? Is that this type of training is ineffective as stated in both instances. In Tokyo Ghoul :re Sasaki is giving advice to the Q's when they are training and he is not berating them while doing so.