Originally Posted by: dlwalkebasically chromatically walking the root of a minor chord backwards until it becomes the 5th of the minor’s relative major (e.g., ACE, G#CE, GCE)[/quote]

Those are fun. They are typically called line cliches. They are more common in jazz & Romantic classical music. So, when used in pop they really stand out. Examples:

Something - The Beatles

Stairway to Heaven - LZ

Time In A Bottle - Jim Croce

Originally Posted by: dlwalkethe intro chords of the James Bond theme progression [Em-Emb6-Em6-Emb6...repeat).[/quote]

Yes! And you can also look at the 3rd chord as an A7 (dom7 IV).

Originally Posted by: dlwalkeMy approach yielded a lot of diminished chords. I’ve often seen diminished triads referred to as rootless dom7 chords[/quote]

Exactly. Common in jazz.

https://www.guitartricks.com/lesson.php?input=16056

https://www.guitartricks.com/lesson.php?input=21171

Originally Posted by: dlwalkeI also saw how impactful different voicings could be on whether or not I thought a particular progression worked. Some progressions initially sounded lousy, but when I played one or more of the chords differently (e.g., Am as an open chord vs a barred chord at the 5th fret), they were transformed into something that sounded really nice.[/quote]

Yes, chord voicing can make or break the sound. Good observation. Most of that has to do with register and voice leading.

Originally Posted by: dlwalkeI also accumulated a ton of time repetitively playing chords and chord transitions (i.e., practicing basic stuff although that was not my goal) over and over and over. So apart from any knowledge-type learning, I’m pretty sure some of my basic skills improved.

That is an outstanding observation. I'm glad you realized this.

[quote=dlwalke]Well, if you're still reading this...

You bet. :)

[quote=dlwalke]I found that voicing the chords differently often had a significant impact on how a particular progression sounded. I think, but am not sure, that this often had to do with the top note.

Usually, all other things being equal. The top note is often regarded as the most prominent or noticable & almost always regarded as the melody note as you correctly observe.

[quote=dlwalke]but I can barely hear the difference between the regular open C and a C with the G played on the 6th string ([332010].

Try that with an electric guitar & a loud amp.

[quote=dlwalke]So anyway, I’m wondering if there is a convention for notating the top note. I know that you can communicate the bass note by using slash chord notation but I don’t think I’ve seen anything comparable for the top note.

Yes, it's called music notation. :) Seriously, this is a good question, and it really highlights how important reading (& writing) music notation is if you want to identify or communicate specific musical information.

Fun topic!