Not sure if there is enough material for a whole book tho.
Should be Chinese. I don't know my father's side of the family, and on my mom side, surname is Kim, but have you met any chinese named Kim? could be Korean?
4D, Gambling, Football Gambling, drug trafficking.
A crazy one, mostly.

Because after i retired, i felt that praying to Guan Yu is abit silly. Yeah i still believe in brotherhood, duty, honor, etc etc etc buttttttttt.......anyways Guan Yu died many many years ago, i feel abit silly praying to Guan Yu.
And i don't really believe in Taoism, i just prayed during that time because it was a requirement.
Anyways, Islam provides peace, guidance, purpose, structure, moral compass,  etc etc.
And i find that Muslims has a certain aura about them. Muslims are good people. i desire to be like one of the many muslims i met.
And to answer another of your question.

Of allllllll the sick fucks i have come across..... They fit into 1 of 2 categories.

A) They care nothing about religion. I am not talking about being Atheist. These people literally don't give a fuck if there is ALLAH or there is no ALLAH.

B) People who go tooooooo deep into any religion. Kiddy fiddling Catholic Priests. Scammer Greedy Manipulating Literally take money from church funds Protestant Pastors. ISIS.    They take everything literally without using their brains.

Spirituality is important.
I don't know. I never needed medical surgery in prison. Most probably they sent to gov hospital with police guard.