How does this sentence 如果你要是查出是谁的话 mean exactly?
This sentence is an awful mistake, in rhetoric, logic and grammar sense:
如果 and 要是 mean exactly same thing: if.  You use one, not both in a sentence.  Your suspicion is justified.  Majority Chinese speakers won't do this, if any, children maybe, as they like to exaggerate.  BTW, 要是 does not necessarily require 的话 as connector.  要是明天下雨(的话)，我就不去了。