None of them compare to the old, beloved, unbeatable WINAMP for Windows, or AIMP, also for Windows. Linux app developers have truly awful taste. Qmmp is the least bad one out of this list of weird choices.

agree – Sayonara is fine for audiobooks as it supports bookmarks, speed, and pitch.

• Playback of the file in playlist starts at 10-20% position. After realizing what I want to do with that file I press one of the custom sorting keys.
• The player tags the file according to the configured value in settings for that custom key and jumps to the next file (to10-20% position).

If the value is “delete” then it deletes the file. Alternatively, the player has a “delete all files with a certain tag” option that can have a confirmation prompt.

I thought that Cmus could be persuaded to such behavior with Autokey but it does not seem to have any file modification functionality despite being a command-line tool.

Quod Libet with Autokey might work, but it requires calling up a context menu to create a tag, no hotkey possible, which makes it slow and unreliable.