Your editor of choice (EoC) likely does not support the -- flag.

The -- flag tells most programs that everything following it is a filename. This is as security feature to prevent accidental application of flags when they are not wanted (Example: $EDITOR -- -V will open a new file named -V).

If your EoC is opening -- as a file, you can either change rifle.conf to not use --, or you could submit a patch to your EoC to support use of the -- flag. It is highly recommended to submit a patch to your EoC.

[BEWARE] Should you choose to edit your rifle.conf, know that you are putting yourself at some level of risk of unforeseen bugs with rifle/ranger!

The configuration option you are looking for is in the rifle.conf file in the config directory (default is ~/.config/ranger/rifle.conf).

The relevant lines in rifle.conf are:
line 86: mime ^text, label editor = $EDITOR -- "$@"
line 88: !mime ^text, label editor, ext xml|json|csv|tex|py|pl|rb|js|sh|php = $EDITOR -- "$@"
line 207: label editor, !mime ^text, !ext xml|json|csv|tex|py|pl|rb|js|sh|php = $EDITOR -- "$@"
(the lines may vary a bit)

Remove the -- from those lines, and restart ranger!

You can either put these lines in your ~/.config/ranger/rc.conf or toggle them during runtime with zi, zP and zp respectively.

set preview_images false
set preview_directories false
set preview_files false

Do you have a disconnected remote file system or inaccessible directory mounted directly under your $HOME ? Try moving it to a subdirectory such as $HOME/remote/target .

It's a tag, and it's stored in ~/.local/share/ranger/tagged. It's created and removed by pressing " (a double quote key) followed by the character to (un)tag the file with. The most common tag to accidentally apply is * by pressing t, which toggles the tag, defaulting to *. You can undo any tag by pressing ut.