1) public transport from jiuzhaigou airport to town , 2) ? km , 3) how much CNY 4) latest by ? time

Do you mean bus from the airport to the scenic spot area? If so, it is about 90km between them. There is shuttle bus running directly from the airport to the scenic spot area. It costs CNY45 for One-way Ticket and CNY80 for Round-trip Ticket. It takes about 1.5 hours. The shuttle bus schedule generally matches flight arrival times if more than 5 persons have purchased a ticket.