Some questions from new developers

Thank you for the explanation.

Anyway, for search purposes, it is best to use English. However, sometimes I may need to change the message ID if there is an error. however, there seems to be a function in translatewiki to automatically search for similar phrases, so maybe changing the message ID won't cause too many problems.

Yes there's such function, however contact the site admins for details, I've not used it but I've seen that there's some known issues and ways to do that correctly. Noite that for now, when a message gets renamed or when the message group is splitted into two separate ones, the moved messages may need to be reviewed again, causing additonal work for translators. I've seen a few phabricator tasks about this.

If you only change a message key, and keep the message content identical, then our system automatically suggests to rename it with all the translations. This is reviewed by translation admin. On next export, all languages will updated with the renamed key.