Just a remainder that it's still not fixed (pasting templates after wikilinks).
Or if it was fixed, that it's broken again.

Since (realtime)Preview for edits of *.js/*.css doesn't have any use anyway (the js/css isn't executed/applied [or is it?]), I think that feature could be disabled in case of such files.

Maybe adding two-brace autocompletion would solve this, since you probably will also add two closing brackets anyway.

Another artifact:
If you style the text that is at the end of a line, as a code, then you can't place the cursor outside of the code block (at the end; you need to "unstyle" the text that you typed after the code block).

Not always it's clearly visible - if you paste template behind a wikilink, you can select only the template. Or so you think, until you copy it and paste somewhere else. You can easily miss that you just inserted wikilinked template.