QuartetCork Tiles, Cork Board, 12" x 12", Corkboard, Wall Bulletin Boards, Dark, 4 Pack (101)

The description says it's 1/4" thick, but several reviewers say it's 1/8" or that it is too thin for regular push pins. Can anyone confirm?

Will the adhesive ruin my wall when the cork boards are removed?

Is this 1/8" thick as some say or 1/4"?

will I need additional adhesive to place cork tiles on plywood rectangular column (hiding drain pipe)?