Business function Compilation

Hi Everyone,
I am new to JD Edwards and often get stuck when working with business functions (both C and NER). I would be grateful if you could help me understand the following:

1. How can we compile a business function using the BSFN Build option?
2. How can we compile a business function in other environments (like QA or UA) if we don’t have administrator permissions to add ourselves?
3. If we add a business function to our default project and then compile it, could it cause issues since the same BSFN might be used in multiple projects?
4. If JDE logs are not available, what is the best way to identify the error in a business function?