Maybe some can be here : https://framagit.org/SondagePro-LimeSurvey-plugin/adaptEnterErrorSurveyText

"How about adding more end URLs for common errors in survey general settings? "
could you please open a separated feature request for this one?

I should make 7 feature requests, one for each error?

What about expanding the language specific section (date format, decimal separator..) with a message table.
That would allow overriding the default messages.

A next step would be expanding the templates section with more pages.
Perhaps even language specific to get more control over the look and feel.
A paused or deactivated survey often needs a individual message instead of a technical term/sentence from the PO-files.

In 3.0 develop, all is done here :
https://github.com/LimeSurvey/LimeSurvey/blob/develop/application/controllers/SurveyController.php#L105

Solution 1 : in template (views) use own string. Maybe we can add $sType for this. Then it was more easily managed.
Solution 2 : Use beforeControllerAction to extend SurveyController and replace this function.

Think we have all now.