There is a taxi stand at the airport. Delays are a common thing and most of the taxi companies won't accept preorders from the airport.
Reception staff can order a taxi for you when you are at the hotel.
Get a cab or Uber from airport. Is likely 15-20 pounds and takes ~20 mins or so if there is no traffic. They can arrange for a car to get back to airport.
No shuttle. we had a rental car so they do provide a parking voucher.
I use Uber ~ in Glasgow they were great.
I didn't check myself about a shuttle
Get an answer from Argyll Western Hotel staff and past guests.