I decided to try KOReader just from curiosity (I don't read books in PDF format). Installation was very simple and easy thanks to the instructions in the first and second post. Many thanks!
(As to the KOReader itself, yes, it has tons of settings and I went through most of them, but no matter what I did, my hand-edited epubs still looked much better in the Kobo default reader. I didn't uninstall KOReader, though. Perhaps I'll need to read a PDF or two on my Kobo in the future, so it can wait its time.)