Understanding directory permissions in UNIX

I've been trying to learn Unix and Terminal a bit better, and I've come across some behavior I don't understand. Hoping someone can explain to me what I'm missing.

Lately I've been experimenting with permissions on directories. From what I (thought) I understood, read permission means you can view the contents of a directory (i.e., ls directory should list the contents of the directory); write permission means you can create, modify, or delete files in the directory (i.e., touch directory/newfile, or vi directory/fileimade, or rm directory/fileihate, all should work); and execute permission means you can make the directory your working directory (i.e., cd directory should work)

But that isn't what I'm finding.

If I have r-- on a directory, I receive errors on attempting cd directory or touch directory/newfile, as expected. But if I run ls directory — well, I don't get an error, but no files are listed, even if I know there are files that I own and/or have rights to within the directory. So, ls has run successfully but with no data to standard output. Why not?

If I have -w- on a directory, I receive errors on cd and ls, as expected. But if I try to create a new file – touch directory/newfile – I also get an error. Why?

All of the x categories work exactly as expected; I can cd into directories with --x, but nothing else. I can cd into directories with -wx, create and delete files, but ls returns an error. And I can cd into r-x directories, list their contents, and work on files for which I have existing permissions, but cannot create or delete files. All these make sense to me.

So what am I not understanding correctly about r-- and -w-?