Well , there are several gods dedicated to different things , so if you wish to work with a god or goddess regarding fertility or well being , it is more useful not to ask for one for example specialising in creation and destruction .
But gods and goddesses can aid you usually universally . And yes, a western banishing ritual can be used in asian lands , it does not matter . There are many forms of doing things , with different manerisms and factors , but all can be used to achieve a result.
A diety can generally aid in banishing of most spirits in general. And also about your sweeping statement about their ideas on the astral realm is also wrong too in my opinion.
Those two are two different places and areas though they may "overlap" and also reside in the astral , but i doubt so . Those are 2 different planes of existence , i beleive. Also , another thing you need to know is that chinese and asians do not need to go to a temple and [project , this is simply for people that have no clue for projecting or travelling out of their body.
So yes , a asian can do "western" meathods of doing things and "a western can do "asian" meathods of doing things.
Also , asking a spirit is different from asking an angel , Chinese usually do not incoparate angels in their workings , so yeah , please take note of the difference .
These things do not exist in a particualr area because they are subject to different cultures and traditions.
FengShui is mainly the usage of placing objects within different areas , corrosponding to different directions or making use of various elements , which they believe as earth , Metal , Soil , Fire and Water to change their Earth luck.
They are also various "western" meathods to change your luck so why must one be subject to one particular order?
Anyway , Here is my main few points
-God and Goddesses have power even in diffferent areas .
-They are more meathods other than FengShui to change your earth luck
-We are not subjected to a particular diety from the moment we are born
-Chinese traditions and ways of doing things usually do not incorporate angels . Please make a difference and take note that the spirit chinese works with are angels . They are not the same so avoid making sweeping statements
-The astral plane issue , is that they reside in different places of existence , so take note. The chinese "underworld" may overlap with the astral plane and may also be part of it but it is not the astral plane in itself.