Okay, I tried this out and I've definitely made headway. I've run into a couple of problems though.
First, unless I'm mistaken, everytime I want to add a new directory or, more importantly, move a folder, I would have to edit the array of folder names in each individual file - I'm trying to avoid this. How would I get the code with the array as an external file that could just be referenced by every page? I was trying out another set of code from this page which just uses folder names instead of an array of replacement names (since I name all my folders according to content, this is fine for me):
Problem is, I can't get it to work - I end up with warnings and almost no content. My test page using the code from that site is here:
Second, when I click on any of the directory links in the breadcrumb trail using the code on the page you suggested to me I end up getting an index of the files in that directory instead of index.html showing up. How can I get around this? As well, in order to have breadcrumbs on each page I won't be able to use index.html anymore, I would have to use index.php (or some other filename); how can I designate what file is opened when it goes to that folder?
Thanks for the help so far!