Thuanvo,
I have the 534’s as side surround that radiate both behind and to the front of the seated position at 45-degree angles. Initially I had them at about ear level but moved them to 2 feet above ear level which I definitely like better especially for sound effects in movies like the ricochet of a bullet over your head and not in it.
As for the rear surround in ceiling you may want to angle the tweeter toward the listener, but I think that is a personal preference. I have 422’s for rears and they are point toward the center of the listening area.
I would try your original installation placement first since you may be pleased with the effects.
What are the other speakers you plan for your speaker setup?
Jack