So this is interesting, I tried to run the CREATE query per your example above:

CREATE TEMPORARY VIEW IF NOT EXISTS view_test AS

select * from ....

But this gave me a exception:

"It is not allowed to define a TEMPORARY view with IF NOT EXISTS"

However, I used a similar query before to create my view:

CREATE OR REPLACE TEMPORARY VIEW view_test AS

select * from ....

This works fine, the query returns: "was successfully executed" but I cant use the view becouse it's not found.