Hello Lee, the thanks are mine to offer - I'm grateful that you've come to participate. Feel free to talk about Chinese gods and Chinese folk religion as much as you wish; any questions are welcome.
It is a misconception that all these gods are 'Taoist deities', actually.

For instance, Taoism does not subscribe to the existence of Na Zha and Guan Yin, among many others.

It is the syncretic form of Chinese religion, which combines some Taoist elements, some Buddhist elements and some Confucian elements, that I refer to as Chinese folk religion or the sintua belief.

However, Chinese folk religion often puts its own interpretation on Buddhist beliefs, Taoist beliefs and Confucian beliefs - see, for instance, our take on Guan Yin.

Also Chinese folk religion has some of its own unique elements, as well.

Trance mediumship - the concept that deities can possess the bodies of human mediums in order to communicate with mortal devotees - is one example. Taoism and Buddhism do not subscribe to this belief, which is very ancient, much older than either of these religions.

Chinese folk religion also accepts a number of non-Chinese belief systems, such as Datuk worship, and includes deities that Buddhism and Taoism either do not recognise at all, or pay the merest of lip service (e.g. the Monkey King and Na Zha).

Hi Nacht, I remember when I was growing up, there are two deities that my dad and mom were praying to and they are situated at the edge of our beds and one above side of stove/cooking area respectively.

I seldom see them being prayed to in modern houses, but never quite too sure why...

Can you share with me what are their stories, their origins, etc.?

Thanks

Thanks for the info with the furnished photos for better understanding.
Further question. Some ppl are "adopted" by some of the gods, mainly Guan Yin. How does this adoption works? My friend when he was very young was adopted by Er Lang Shen. He was too young to remember and then his parents divorced. He followed the father and later became Christian. Then he grew up and said he had dreams about this "3-eyed" guy. He later found out about the adoption from his mum

Nope. Just that now he knows who is this 3-eyed guy in his dreams and he is not so afraid anymore. He is not a devoted Christian and doesn't go to church anyway 

Most of the ppl I heard are adopted by Guan Yin. Seldom heard adopted by Er Lang Shen or other deities. Those adopted by Guan Yin, some of them can't eat beef completely, some can eat outside but cannot bring home. Some had diarrhea after eating beef

I heard that for ppl praying to Guan Yin at home, she won't be at the altar all the time. She will going around. But for some ppl who can see something, they will see some pink smoke that means she is in the house

You are not typing words from any Chinese dialect that I understand.

How about giving me the name in Chinese characters?