Key triangle using on-camera flash

[ccting]

i am total noob of lighting..So far, i only own on-camera flash, and the only speedlight i have is iTTL YN465. This is the only equipment I use to learn lighting together with the book "light science and magic". I came across this "key triangle" after bored reading the first 2 chapters.. I used on-camera bounce back method to gain the 45 degree lighting

Questions:
a) Is the key triangle correct????
b) How come I can't eliminate the skin texture using diffuse light from paper? too far to the left? light souce too small? Or it falls within family of angles? Using GOBo? or using Polarized light and len filter?
c) How come i can't see the iris? I am using my only len vr kit 18-55mm. f/8, 1/60s, ISO 100, on-camera flash.

The below is the original, and 2 existing lightroom presets

DSC_0216-6.jpg Original,
DSC_0216-3.jpgHigh contrast preset,
DSC_0216-5.jpg Lightroom preset (review highlight / kicker)

Single light source of On-camera flash with diy black card to learn key triangle, kicker, family of angles, cropped to 100%

Thanks for your advices...