What?
You are confusing the warrant requirement, which is completely separate from the reasonableness of a search.
I'm not sure how you are coming up with what you think is th analysis, but every law school textbook, supreme court opinion, etc, will tell you that you start with whether the search was reasonable.
If the search was reasonable by law , there is no 4th amendment violation. Period.
Maybe you are confused because they often say these are not searches? For example, you will read that doing helicopter flyovers, even when looking in people's fields, is reasonable (which at the time, meant it wasn't a violation of the subject's reasonable expectation of privacy), and thus, not considered a search that is subject to the rest of the 4th amendment. This isn't because it's "not a search" in reality, it's because the 4th only protects against unreasonable searches and seizures, not all searches and seizures, and thus, for the rest of 4th amendment purposes, it's not a search.
If the search was not reasonable, it either has to fall into an exception, or requires a warrant.
Now, current jurisprudence considers most searches without a warrant unreasonable (subject to plain sight, automobile exceptions, etc), but that is irrelevant to the steps in the analysis.
You seem to be mixing a lot of the analysis and requirements around.