I don't agree with use 喂 to replace 你好，it sounds impolite.Say HI is ok to everyone.

we usually use 嗨 which pronounced in "hi " 

really? "nee how?" ?  Ni hao 你好

1 word - pinyin, google it.

in that case you can also say Wei4 喂 which means hey, or ni3 zen3 me yang4 你怎么样 which is how are you, or 你好吗 which in your constrewn dictation would be "nee how mah" or ni hao ma