Those incorrect password attempt were from yesterday before I made the initial post, when I tried to follow the instructions from that other thread. I just figured out now the problem was I was entering the admin password, which was coming up incorrect, so I tried the "student" account password which students use to log in.
Using that correct password, I now get the following message in terminal after typing in the chmod 755 code:
"student is not in the sudoers file. This incident will be reported."
I also searched in Finder for those 5 files/folders. Only one came up, /usr/local/lib/neko, so I deleted that.
Attempted to run a game in Stencyl and still no luck
I wish I could simply revert back to version 3.3.2, but I read that certain things like the Crash Course doesn't work (which my students use to learn the program)...
Let me know if you have any other suggestions.