Really neat post, I’d not heard of a few of these (never knew libre office draw could edit pdfs!).
Couple of extra ones:
Note taking and pdf annotation: Xournal++ is amazing, it’s also great to use on larger whiteboard screens. Plug and play support for scribe tablets on both windows and Linux.
Emulation (up to ps1): Mednafen is lightweight and comes with a gui. It also supports recording, though not netplay.
Ebook management/reading: Calibre - allows easy importing and exporting of ebooks to devices, also has a great built in search letting you find DRM free versions of a book.