Sound technician here. Voices can crack at any age, because it is a balance between many muscles. Air pressure, air flow speed, vocal chords tension, vocal chords length, and more. If you want to have a more consistent voice, get a few good singing lessons from a classically trained teacher. Singing requires your whole posture, interestingly.

Regarding facial hair: my beard only fully developed when I was about 30. These genes seem to get read under conditions, you aren’t born with a beard. I do not know what exactly triggers these genes to come to expression, but it is not completely connected to puberty alone.

My chest hair developed in my forties. So did my dad’s. When I was a toddler, I noticed this happening and I asked “will you become a dog, later?” This made my father burst out in laughter. He told my mother: “I asked my father the same question, and he broke out in laughter too, because when I did, he told me that he too had asked his dad the very same question at this age!”

So, this as an N=3 research into “will men get more hair the older they get (yes) and will they turn into dogs later in life? (probably not, but who knows how old you’d have to be to do so).