I would take the time to really learn how the module system works as you’ll find it’s likely more sane than you think. It’s not a huge topic but more than I can type out here, but the docs do a good job.
A few points that may be helpful (that expand on @sorentwo’s answer):
import doesn’t work like it does in many languages. As touched on by @sorentwo, you don’t have to import a module to use it, they are all always available. import is for importing functions (and macros), and only functions (and macros), you cannot import variables or module attributes.
There is no way to magically affect what is available inside a defmodule from the outside. The exception is that every module has an implicit import Kernel which contains such important functions/macros as + and def. This is hard coded into the compiler and there is no way to do this with any other module. If you see just the following:
defmodule A do
def foo do
B.foo()
end
end
B is a top level module, full stop. If it’s not in your project it’s either from a library or it’s builtin.
If you see this:
defmodule B do
def foo do
foobar()
end
end
…that’s a compilation error 
Without any imports or uses, there is no way to make a random function call like that work.
As you correctly identified, a wrench is thrown into things as soon as you see a use. This means there are macros and therefore metaprogramming at play. It is encouraged to always have a callout block in the documentation to describe what useing your library will do, so usually you can look to the docs to know what’s up.
It’s very important to at least get comfortable with the ideas of macros because from a technical standpoint (not trying to be reductive here, BEAM friends), Elixir’s powerful and well-designed macro system is the thing it’s bringing to the table as a BEAM language. There are other really good reasons to be here like the community, the syntax, and of course the libraries, but a lot of the best libraries and projects are so good because of macros. I’m absolutely not trying to discourage you from getting to know Elixir better, but the cool thing is that if you decide it just isn’t for you, there are other great macro-free BEAM languages like Gleam and, of course, Erlang itself! But I think it’s worth it to stick to Elixir 
