Pagemaker 6.5 conversion

Of course, you need to adjust your expectations of how "perfect" the conversion will be. You WILL have reflow to deal with, and if your graphics and links were embedded in the PM document as opposed to linked, the conversion will not convert them. You may not necessarily need it to be a perfect match anyway, so converting will get you "mostly" there. Plus, you will have font issues in recent versions of ID if you used Type 1 fonts in the past, so you will have to deal with replacements.

To answer the second part of your question first, yes; Any ID file from even before CS will open in any version of InDesign, so most definitely a CS4 file will open.

As far as the EDU version, I don't believe there's any issue with it not having the capability, but there's a way to check: Within InDesign's application folder, check the Plug-Ins or Resources Folder (whichever exists) for Filters. Inside that there will be a folder named "Sangam Readers". If you have "Reader for pagemaker.smrd" within, you're good to go.

See this thread for information about this issue:

https://community.adobe.com/t5/indesign-discussions/how-to-open-a-pagemaker-6-5-file-in-indesign-2022/td-p/12632656