Have you checked your antivirus software to see if you have whitelisted Scrivener.exe? It is often the solution to access problems.

...under the Corrections tab in Preferences...

You cannot turn off the underline without turning off "Check spelling as you type." That option, and the ability to choose dots or waves for the line style, are under File / Options / Corrections / Spelling.

(BTW-- Regex worked brilliantly! )

I spaced out when reading your reply. Sorry for my useless answer.

Their RegEx spec is this one: https://perldoc.perl.org/perlre

I tried choosing RegEx as the search operator and the escaping the leading dash with a backslash and that worked in my little test file.

Look at File / Options / Appearance / Main Editor. Do you by any chance have "Use fixed width editor" turned on? If so, turn it off.

Perhaps a leading dash has some particular meaning?

Yes, it does. See page 213 of the user manual under "Finding things that don't have a word." It could explain why you are seeing blank documents in the results list.

Failure to save a document is often caused by antivirus software getting in the way. You can usually stop that by opening your antivirus software and whitelisting Scrivener.exe.

Don't highlight the word. Just place the caret somewhere in the word, then do your normal Related Words actions.

I'll assume you're running Windows 10. If not, look at Control Panel -> User Accounts, find your account, and see if Change Name is available. Under Windows 10, the Setting applet has no place for you to change your user name, but there is another way. Scrivener is apparently using the USERNAME loca...

Just type over the name shown at the beginning of the comment.

You can create a custom template that contains those keywords (section 5.4.3 of the manual), or you can copy files and folders between projects (page 79 of the manual). There may be other ways, but searching for "keyword" in the manual gives these two right away. What's "best" is...

the empty category will be deleted and a new one created for the custom name. A minor UI issue: when the category name is changed, a new entry does appear in the project templates list, but the old category, that now contains no templates, is still in the list until you close the templates list and...

When selecting New Project from the File menu, the Project Templates dialog appears, but there is no template name where I would expect to see "Custom" or something similar. Editing the template info (other than leaving the category as "Custom") does nothing. Project templates - ...

I posted to that thread...

You may not get an answer there. That is the Beta Release forum, which can be replied to, but no new messages are allowed. And I think many people have stopped looking at that forum, now that 3.0 has been released.

You could start with this thread and the one it references to see if any of it applies to you: viewtopic.php?f=57&t=65749&p=334092&hilit=lag#p334092