You gave the wrong definition of shen (神). Either you can't read Chinese or you don't know how to use an online dictionary.

Nothing you described has any resemblance to common Taoist/folk religion mythology among the Chinese diaspora. I described what is common in the folklore. If you don't recognize it at all, you simply don't know what you're talking about.

You probably subscribe to some new age guru bs that combines Eastern mythology with good old Christianity.

>The word is Shen, which more similar to a Saint in English.

False. Shen can mean deity or god. It's interchangeable. There's also no concept of a "one true God". That's a feature in Abrahamic religions. So you can't just squeeze it into a different context.

There's also Xian, which means immortal. Mostly in Taoist folklore where it is believed that some people achieved immortality by spiritual cultivation or other means. They're also part of the pantheon.

In the folklore, the pantheon operates more like a government where each deity/immortal has a duty or office they're in charge of.

>When you go to a temple, you are asking for that Shen to pray for you. On your behalf. Because that religion you do not have access to God.

Not the case here. Whatever you're referring to appears to be some sort of Christian sect.

BMI is perfectly fine to use for most individuals who aren't athletes. Because the only instance it isn't a good estimate for obesity, is with high muscle mass. The vast majority of overweight people are not athletes and it's extremely unlikely that they have high muscle mass.