So functional programming is basically using prebuilt libraries anf functions and not write a single line of logic?

Functional programming is an approach to create a code by constructing methods to either create a user defined sets of libraries.. so using prebuilt libraries/functions are not necessarily included it all depends on the needs of the program...

Yes and do not let anyone tell you otherwise.

So is oop in Java EE. We just code large and complex hierarchies which do something that rails or django would do with absolute transparency in 1 line of code, but ours is better cuz it takes hundreds or thousands of lines of code more.

This sums it up pretty well in my opinion http://lihaoyi.com/post/...