When two words are put together as in "heads up", "put down", "build out"... are they considered a phrase? And if so, do the term for these are "adjectival phrases" as they mention on this question: Is "put together" an adjectival phrase?.
For the basic question of whether the words constitute a phrase, the answer is a Yes.
Whether the pair of words constitutes a phrasal verb, an attributive phrase or another depends on the particular words and their implication.
Also, when the words so together serve to convey a certain definite sense, different from the meanings of the individual words, and this sense is accepted over time, they are generally called a 'set phrase'.
Further to this, I feel your post has too many questions in one and is ambiguous.