Exported functions can be called (or, rather, located and addressed) from the outside - so, whenever you need a function to be addressable from the outside you (or compiler/linker) make it exported. This is the only rule :)

Normally WinMain is not exported in DLLs. What happens is that WinMain is not called directly by the loader (and main(), likewise). The code that calls it, is a bootloading code, which is addressed by a DLL/EXE entry point. This code does all the initialization and at the end of it calls into WinMain/main(), the address of which is known during compilation.

You can use queries with orderby clause - then you can have your displayOrder as a part of your Track schema and make sequence ordering by this parameter while maintaining Dictionary capability.