We have a guy with full sleeves and still wears short sleeve shirts and couldn't care less what people may or may not think. While flying with him, all I hear are compliments from pax and other workers though.
I have 3-4 visible arm tattoos while wearing short sleeves. I just wear long sleeves to the interview and first few days of training until I can get a feel for the atmosphere. Have never heard any complaints. Was actually encouraged by the cooler of the two asst. chiefs to get full arm sleeves.