Apple cider is a good replacement.
White wine vinegar would be the best substitute, if you have it on hand.
Any white wine would substitute for champagne.
No. Cooking wine does not contain vinegar, and would introduce too much salt.
Yes but you will change the outcome
Yes.
Substituting one for the other would significantly change the taste of the resulting food.
As long as you pick a wine of similar dryness. Chardonnay is a medium wine (not dry as many people often make the mistake of thinking). Pick an average medium white and it should be fine.
A mild and sweeter western vinegar such as champagne vinegar or white wine vinegar will substitute
White wine vinegar is the better substitute for rice vinegar.
You can, but white balsamic tastes stronger than white wine vinegar, so you may want to reduce the quantity that you use.
No, vinegar contains no wine and tastes very different than sherry.
If color is not important, red balsamic vinegar would be the best substitute for white. Otherwise, a sweet white wine would be a possible replacement.