Opinions on Use of Black and White in Portraiture?

Hi! I'm new to this group as well as the hole of Fstoppers so this is my first post :)
I wondered what peoples opinions are on when to use black and white in portraiture?
I generally just use it to cut out distracting colours or to de-clutter the background.
Are there any other rules people use when considering black and white...

Model: Lisa Rejen

Model: Lisa Rejen
Photographer: Bram van Dal

Camera settings:
Shutterspeed: 1/500
Aperture: F / 2.5
Iso: 100
Camera: Canon 5dmkII
Lens: 85mm

Location: Strijp-S in Eindhoven.

With this photo I have the model on the elevation where you already get a different perspective in the photo....

Eastern Beauty - Constructive Critique Accepted

This image is from my last trip to Asia and I found this area by accident. I couldn't help but feel drawn in by the lines and the energy of the trees and water. I chose the black and white treatment because I often get distracted by color when looking at older structures.

Admin Building B&W

My use of Ansel Adams' tones on one of my favorite buildings to shoot. Let me know what you think. I'm taking a break from color and really focusing on getting the tones I want in black and white. Constructive critiques welcome.

Studio Portrait

Studio Portrait!
Canon 5D Mark IV, 85mm F/1.2, F/14, 1/200s, iso 100, 2 Lights setup, Beauty dish with grid, backlight and Silver Reflector under the face!
Arber Elezi Photography

Looking for Critique :)

Hi. I took this picture of a beetle which landed on my glass whilst I doing some macro photography.
I tried to go for a minimalist feel for the image which is why I chose to make the image black and white. Any opinions or critiques would be great.
Thanks :)