You can add shortcuts to your gamelist that will start with an empty file, thus disabling the auto-loading. Some emulators already have a similar shortcut (+Start Amiberry, +Start Fuse), you can replicate the setup for others.

If you prefer working from the desktop, then you can leave RetroPie alone and just install the emulators manually on a Raspbian + Desktop image.

@tinydog1968 There's a thread with many legal sources for games in this forum, and @SgtJimmyRustles kindly posted a link to a wiki with even more.

You could also look for "best games for [system name]" (e.g. "best games for snes") on the web or on YouTube to find games that are the ones worth playing.

oh wait i had to restart