Obsidian publish questions

I have several questions on Obsidian publish feature and related workflow.
My goal is to store pdfs (papers + books) and a “wiki-like” system of documentation to them. Preferably, I would want some wiki pages and some files to be password protected.
Currently I store it in Dropbox folder, having a vault in the root. In the vault I have links to pdfs.
I would love to have a web site with access of the inside. I have tried Github Pages before, but storing pdfs are against the rules and are a little controversal to the whole idea of github.
I don’t think my problem is unique, so I’m wondering if someone has an established routine for it.
Small side questions:
– Can I somehow upload big files (some books are over 50Mb)? If no, what would be the easiest way to make such a website on a third-party server (I can use Jekyll to host GH-pages for example, is there “kernel” of obsidian publish)?
– Is there a way to link a specific page in pdf? [Extremely handy, saw that in org-mode]

Also is there a way to automaticly update the published version (like dropbox, a script to check for updates and autopush)