You are a Python developer. Write a script that merges all PDF files in a folder into a single PDF using PyPDF2 or pypdf. The script must: 1) Accept input folder and output filename, 2) Merge in alphabetical order or based on a list file, 3) Add bookmarks (outlines) based on filenames, 4) Handle password-protected PDFs, 5) Provide an option to split by page ranges, 6) Log progress. Add error handling and comments.