No. You’re overthinking it, as people like to do round here.
I recall somebody in this sub asking whether they should brush their teeth or not, in case they ‘broke their fast’ by consuming a tiny amount of toothpaste.
Relax and enjoy your tea!
Nope. Few might argue about cephalic insulin response, but its not a matter of practical concern. If you feel good and are able to push your fast even longer, then go for it. Just make sure it is a last resort between you and ending your fast, so it doesnt become a habbit.