For the quote thing, you can enable to auto close quotes in the settings. Just make sure " is in the list of enclosing characters.
I didnt do any of that for quote.
Under Snippet I just put: [QUOTE] ${cursor} [/QUOTE]
and that works.
I def agree it slows down my typing and as of yet, I cant make this work as well as it does on gedit snippets.
Simply write your own script then, it will be faster and better than any other method because you can do exactly what you want
See Helper kate script to wrap a string with QStringLiteral("") ($1837) · Snippets · GitLab
It’s an example script that I use myself. You can modify the above and make it do what you want.