No, vinegar contains no wine and tastes very different than sherry.
Definitely not.
You could substitute rice vinegar for cooking sherry. Rice vinegar has a mild, sweet flavor.
White wine vinegar would be the best substitute, if you have it on hand.
Yes, if an acidic factor is all you are interested in. Sherry vinegar would be the next closest substitute but the taste of dry or sweet sherry for a sauce or marinade is fairly distinctive and to a discerning palate, quite noticable.
Yes you may be able to use rice wine instead of dry sherry,most recipes when asking for dry sherry state either or can be used.
A mild and sweeter western vinegar such as champagne vinegar or white wine vinegar will substitute
Probably you can since both are derived in one way or another from white grapes. All vinegars are weak solutions of acetic acid in water, and are produced through fermentation of sugar-containing substances of one sort or another. Balsamic vinegar is an Italian concoction made from the must of the white grape; sherry vinegar is fermented from sherry (of course) which is a fortified white wine of Spain. You could also use plain white vinegar and add a bit of sherry or white wine. Each will impart a slightly different flavor.
White wine vinegar is the better substitute for rice vinegar.
Sherry is a fortified wine, usually brown in color. Wine vinegars are the result of bacterial action increasing the acidity in wine while lowering the alcohol content. Sherry vinegar is a type or sub-set of wine vinegar, often sweeter that most wine vinegars, started from Sherry wine. While other types of wine vinegar often show up in vinigrettes and salad dressing, due to its sweetness and stronger flavor, Sherry Vinegar does so rarely if at all. Other types of wine vinegars include red, white, champagne etc. Sherry vinegar is often used as a substitute for sweetened rice vinegar (Mirin).
No, because sauternes is a sweet white wine, while marsala and sherry are red and can be dry.
No. Cooking wine does not contain vinegar, and would introduce too much salt.
Two different items you will change the outcome of the dish. I would stick to the recipe.
You can, but white balsamic tastes stronger than white wine vinegar, so you may want to reduce the quantity that you use.