Preserving using cider vinegar

Cider vinegar is fine for preserving and gives a milder taste to pickles.  For chutneys it cause the end result to have less bite, so make a small batch first and check you like the taste before making loads of anything.

Sugar can be in a recipe for the preserving effect, so it is not always a good idea to reduce it.  Without seeing the recipe it would be hard to say whether it was just for taste or not.

Sainsbods sell an organic white vinegar that is 6% it's not a cider one though.

Sainsburys organic white vinegar