there isn't one as tarragon is such a subtle flavour
Yes. The apple cider flavor will be much milder than with the tarragon.
Tarragon can be substituted for anise seed. Another substitute can be fennel seed. Try a pinch of crushed fennel or anise seed as a substitute for a teaspoon of tarragon.
yes because it is a good substitute.
no it can not it will fizz and explode.
Tarragon is one.
No use tarragon instead
A mild and sweeter western vinegar such as champagne vinegar or white wine vinegar will substitute
White wine vinegar would be the best substitute, if you have it on hand.
It can work slightly, but will not be as good.
Lemon juice can be depending on what you are using the vinegar for... in pancakes for the chemical reaction... yes. Try it, and you make the call.
A good quality "red wine" vinegar would be the most logical choice, though one could substitute cider vinegar.
Citric acid is a good substitute for vinegar. Just use Lemon or Lime juice instead of vinegar.